Papers - Tanabe, Takasumi

Mechanically Actuated Kerr Soliton Microcombs

Fujii S., Wada K., Kogure S., Kumazaki H., Tanabe T.

Laser and Photonics Reviews 18 ( 9 )  2024.09

ISSN  18638880

　View Summary

Mode-locked ultrashort pulse sources with a repetition rate of up to several tens of gigahertz greatly facilitate versatile photonic applications such as frequency synthesis, metrology, radar, and optical communications. Dissipative Kerr soliton microcombs provide an attractive solution as a broadband, high-repetition-rate compact laser system in this context. However, its operation usually requires sophisticated pump laser control to initiate and stabilize the soliton microcombs, particularly in millimeter-sized ultrahigh-Q whispering-gallery resonators. Here, a mechanically actuated soliton microcomb oscillator is realized with a microwave repetition rate of 15 GHz. This enables direct initiation, subsequent long-term stabilization, and fine tuning of soliton combs without pump laser tunability that is generally required for soliton microcomb operation. The prospects for using this method with a wide range of applications are revealed that will benefit from mechanical soliton actuation such as optical clocks, spectral extension, and dual-comb spectroscopy.

• Access to Document (DOI)

Exceptional point proximity-driven mode-locking in coupled microresonators

Imamura R., Fujii S., Nakashima A., Tanabe T.

Optics Express 32 ( 13 ) 22280 - 22290 2024.06

　View Summary

We show theoretically and numerically that mode-locking is feasible with a coupled-cavity system with gain and loss, notably, without any natural saturable absorber. We highlight that in the vicinity of the exceptional point, system Q exhibits substantial modulation even with minor refractive index changes and a minimal Kerr effect contribution. Leveraging this unique behavior, we propose an unprecedented approach wherein the lossy auxiliary cavity functions as an efficient artificial saturable absorber, thus facilitating mode-locking. This approach is not only novel, but also presents considerable advantages over conventional systems where both gain and saturable absorption are contained within a single microcavity. These benefits include reduced operational power and ease of post-adjustment, achievable through the manipulation of the coupling strength between the two microcavities.

• Access to Document (DOI)

Compact photonic crystal spectrometer with resolution beyond the fabrication precision

Sugano R., Kokubu J., Jin S., Kodama T., Hofs J.J., Zhang J., Okano M., Tanabe T.

Optics Express 32 ( 12 ) 21563 - 21576 2024.06

　View Summary

We present a compact silicon photonic crystal spectrometer with a footprint of 740 × 9 μm2 and excellent wavelength resolution (∼0.01 nm at single and <0.03 nm at multiple wavelength operation) across a telecom bandwidth of 10 nm. Although our design targets a wavelength resolution of 1.6 nm, within the current state-of-the-art fabrication precision of 2 nm, we achieve a resolution that exceeds these limits. This enhanced resolution is made possible by leveraging the random localization of light within the device.

• Access to Document (DOI)

Synchronization of two chaotic microresonator frequency combs

Moreno D., Fujii S., Nakashima A., Lemcke D., Uchida A., Sanchis P., Tanabe T.

Optics Express 32 ( 2 ) 2460 - 2472 2024.01

　View Summary

We explore the synchronization of chaotic microresonator frequency combs, emphasizing the modulation instability state, which is known for its inherent chaotic behaviors. Our study confirms that the synchronization of two such combs is feasible by injecting the output from the lead microresonator into the next microresonator’s input. We also identify the optimal parameters for this synchronization. Remarkably, even partial injection from the leader is sufficient for synchronization, paving the way for versatile future system configurations. Such systems could simultaneously utilize distinct spectral components for synchronization and transmission. This work advances our understanding of chaotic microresonator combs, showing them to be pivotal elements in next-generation optical communication systems.

• Access to Document (DOI)

Dispersion Engineering of Crystalline Microresonators for Optical Frequency Comb Generation beyond C-Band

Takabayashi R., Kodama H., Tanikawa K., Kakinuma Y., Tanabe T., Fujii S.

16th Pacific Rim Conference on Lasers and Electro-Optics, CLEO-PR 2024  2024

　View Summary

We detail a dispersion engineering strategy for microresonators allowing us to generate microcombs in the near-infrared and mid-infrared regimes, and identifying optimal shapes for achieving anomalous dispersion suited to different wavelength regimes.

• Access to Document (DOI)

Demonstration of Nighttime Thermoelectric Power Generation with Radiative Cooling Utilizing Low-Cost Commercial Materials

Tanto Y., Yomoda A., Kokubu J., Sugano R., Tanabe T.

16th Pacific Rim Conference on Lasers and Electro-Optics, CLEO-PR 2024  2024

　View Summary

We conducted controlled experiments on nighttime thermoelectric generation using cost-effective, commercially available materials under various weather conditions, both with and without a blackbody filter for radiative cooling, achieving efficiencies of up to 53.3 mW/m2,.

• Access to Document (DOI)

Fabrication of silicon nitride based high-Q microring resonators prepared by the hot-wire CVD method and their applications to frequency comb generation

Sota S., Handa K., Fujii S., Tanabe T., Uzawa Y., Furusawa K., Sekine N.

Optical Materials Express 14 ( 5 ) 1128 - 1138 2024

　View Summary

Fabrication of silicon nitride (SiN) based high-Q microring resonators prepared by the hot-wire chemical vapor deposition (HWCVD) method is presented. By the virtue of low-stress HWCVD films, no special precautions against crack propagation were required for high confinement waveguide device fabrication. By using an additional annealing process, the intrinsic Q factor in excess of 5 × 105 was obtained in the telecommunication C band, and which allowed us to observe frequency comb generation. We also investigated into the anneal temperature dependence of the residual hydrogen concentration in the film as well as the optical properties of the microring resonators.

• Access to Document (DOI)

Vicinity of exceptional point-induced mode-locking in coupled microresonators

Imamura R., Fujii S., Nakashima A., Tanabe T.

CLEO: Science and Innovations, CLEO: S and I 2024 in Proceedings CLEO 2024, Part of Conference on Lasers and Electro-Optics  2024

　View Summary

A coupled-cavity system with gain and loss enables mode-locking without natural saturable absorbers. Our theoretical and numerical findings demonstrate significant modulation in system Q near the exceptional point (EP), even with minor refractive index changes and minimal Kerr effect involvement.

Transmission in the 300 Ghz Band Using a Soliton Comb

Imamura M., Yomoda A., Tanikawa K., Kogure S., Sugano R., Kawanishi S., Fujii S., Tanabe T.

16th Pacific Rim Conference on Lasers and Electro-Optics, CLEO-PR 2024  2024

　View Summary

We generated terahertz waves at 300 GHz using a soliton comb, focusing on characteristics such as low phase noise, and successfully demonstrated an error-free 10 Gbit/s transmission with a bit-error rate below 10-9.

• Access to Document (DOI)

Towards Deterministic Perfect Soliton Crystals in Microtoroids with Saturable Absorption

Matsuyama H., Takano A., Imamura R., Wang H., Fujii S., Tanabe T.

16th Pacific Rim Conference on Lasers and Electro-Optics, CLEO-PR 2024  2024

　View Summary

We utilized silica microtoroid resonators to achieve high repetition rate mode-locking and perfect soliton crystals. We then transfer graphene onto microtoroids to enable saturable absorption and study the impacts on its properties, including the Q value.

• Access to Document (DOI)

Study on Chaos Synchronization of Cascaded Microresonator Optical Frequency Combs

Lemcke D., Moreno D., Fujii S., Nakashima A., Uchida A., Tanabe T.

CLEO: Science and Innovations, CLEO: S and I 2024 in Proceedings CLEO 2024, Part of Conference on Lasers and Electro-Optics  2024

　View Summary

By numerically investigating the synchronization of cascaded microresonator frequency combs, we find the optimal transmittance parameters and discover that partial injection from the leader is sufficient. We also present preliminary experimental results.

Soliton Comb Generation Using a Small Prism Coupling Module

Mototani Y., Fujii S., Kimura S., Hashimoto Y., Yamakawa T., Imamura R., Tanabe T.

16th Pacific Rim Conference on Lasers and Electro-Optics, CLEO-PR 2024  2024

　View Summary

We developed a compact prism coupling module conforming to the 1U CubeSat standard and demonstrated soliton microcomb generation with an ultrahigh-Q MgF resonator to explore the robustness of the miniaturized multi-wavelength light source.

• Access to Document (DOI)

Small-error transmission and filter operation at 300 GHz using dissipative Kerr soliton frequency comb

Yomoda A., Imamura M., Tanikawa K., Kogure S., Sugano R., Fujii S., Kawanishi S., Tanabe T.

CLEO: Science and Innovations, CLEO: S and I 2024 in Proceedings CLEO 2024, Part of Conference on Lasers and Electro-Optics  2024

　View Summary

Using a soliton microcomb, we generated 300 GHz waves and demonstrated a transmission experiment at 10 Gbit/s with an ultra-low bit-error rate of 10-9. We also demonstrated a photonic filter in the 300 GHz region, which adds another functionality in the terahertz regime.

Mechanical Actuation of Kerr Soliton Microcombs in Ultrahigh-Q Crystalline Microresonators

Fujii S., Wada K., Kogure S., Kumazaki H., Tanabe T.

16th Pacific Rim Conference on Lasers and Electro-Optics, CLEO-PR 2024  2024

　View Summary

We demonstrate a mechanically actuated soliton microcomb with a microwave repetition rate of 15 GHz in ultrahigh-Q crystalline microresonators. This enables direct initiation, subsequent long-term stabilization, and precise tuning of soliton combs.

• Access to Document (DOI)

Versatile tuning of Kerr soliton microcombs in crystalline microresonators

Fujii S., Wada K., Sugano R., Kumazaki H., Kogure S., Kato Y.K., Tanabe T.

Communications Physics 6 ( 1 )  2023.12

　View Summary

Microresonator-based optical frequency combs emitted from high-quality-factor microresonators, also known as microcombs, have opened up new horizons to areas of optical frequency comb technology including frequency metrology, precision sensing, and optical communication. To extend the capability of microcombs for such applications, large and reliable tunability is of critical importance. Here, we show broad spectral tuning of Kerr soliton microcombs in a thermally controlled crystalline microresonator with pump-detuning stabilization. The fundamental elements composing frequency combs, namely the center frequency, repetition frequency, and carrier-envelope offset frequency, are spectrally tuned by up to −48.8 GHz, −5.85 MHz, and −386 MHz, respectively, leveraging thermal effects in ultrahigh-Q crystalline magnesium fluoride resonators. We further demonstrate a 3.4-fold enhancement of soliton comb power resulting from thermal expansion with a temperature change of only 28 K by employing quantitative analyses of the fiber-to-resonator coupling efficiency.

• Access to Document (DOI)

Stability and mutual coherence of Raman combs in high-Q silica microresonators

Sugawara S., Fujii S., Kawanishi S., Tanabe T.

Optics Continuum 2 ( 7 ) 1588 - 1596 2023.06

　View Summary

We investigated the stability and mutual coherence of a Raman microcomb in a silica microrod resonator by monitoring the output power and longitudinal mode spacings. The results indicate that we can obtain a stable Raman comb formation without the need for four-wave mixing processes. The use of a Raman comb will open the possibility of simplifying the setup because it will relax the phase matching condition usually required for microresonator frequency comb generation. Although there are some restrictions in regard to using a Raman comb for applications due to the coexistence of the comb components in different mode families, a proof-of-concept demonstration shows that it is sufficiently stable and robust for applications such as optical communications.

• Access to Document (DOI)

Assessment of the Feasibility of Employing Chaos Synchronization in Two Cascaded Microresonators for Secure Data Transmission

Lemcke D., Moreno D., Fujii S., Nakashima A., Uchida A., Tanabe T.

2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023  2023

　View Summary

As the limits of computational power continue to increase, concern has arisen regarding insufficient security along with a demand for improvements in encryption methods for data transmission, which might be achieved by chaos synchronization [1, 2]. Using modified Lugiato-Levefer equations (LLEs), we numerically explore two cascaded microresonator frequency combs [3]. To obtain a chaotic state, both cavities are pumped by continuous-wave lasers until modulation instability (MI) combs are generated. By injecting the output of the first resonator into the second resonator, both chaotic fields in the cavities are synchronized. In this work, we investigate to what extent the chaos is synchronized and how this phenomenon may be implemented in existing data transmission systems over a chaotic channel to enable secure communication.

• Access to Document (DOI)

A small spectrometer with extremely high resolution (0.07 nm) realized with an improved reconstruction algorithm

Tanabe T., Kokubu J., Sugano R.

International Conference on Metamaterials, Photonic Crystals and Plasmonics    291 - 292 2023

　View Summary

We successfully reconstruct the spectrum of a multi-wavelength input by using the inverse matrix method for data obtained with a random chirped photonic crystal waveguide.

Field Demonstration of Low-Latency Massively Parallel Communication with Microresonator Frequency Comb

Tanikawa K., Fujii S., Tanaka S., Tasaka S., Wada K., Kogure S., Kumazaki H., Kawanishi S., Tanabe T.

2023 Conference on Lasers and Electro-Optics, CLEO 2023  2023

　View Summary

We demonstrated low-latency optical transmission with a microresonator frequency comb using a 9-km optical fiber in a metropolitan area. The delay time of the entire system, excluding the transmission fiber, was only 3.1 us.

Synchronization of microresonator frequency combs in chaotic regime

Moreno D., Fujii S., Nakashima A., Uchida A., Sanchis P., Tanabe T.

Proceedings of SPIE - The International Society for Optical Engineering 12407 2023

ISSN  0277786X

　View Summary

We numerically study the chaotic synchronization of microresonator frequency combs. The chaotic state of microresonators could be a key factor in optical communications because the modulation instability state (chaotic) has a larger output than the soliton state (stable), which may enable us to realize a higher signal-to-noise ratio. In addition, it will allow secure communication. We show that two microresonator frequency combs in a leader-follower configuration can be synchronized in chaotic regimes. Interestingly, the follower comb synchronizes even when some longitudinal modes of the leader comb are absent. We also show that the Turing pattern comb in the follower ring becomes chaotic and synchronizes when we inject the leader's modulation instability comb.

• Access to Document (DOI)

Small Spectrometer with Extremely High-resolution (0.07 nm) Realized with an Improved Reconstruction Algorithm

Kokubu J., Sugano R., Ohtsuka M., Yokoyama N., Okano M., Tanabe T.

CLEO: Science and Innovations, CLEO:S and I 2023  2023

　View Summary

Spectra are reconstructed by capturing wavelength-specific patterns of localized light in a photonic-crystal-waveguide. We show that real-time reconstruction at a wavelength resolution of 0.07 nm is possible by using low-rank approximation with singular-value-decomposition and regularized-least-squares.

• Access to Document (DOI)

Small Spectrometer with Extremely High-resolution (0.07 nm) Realized with an Improved Reconstruction Algorithm

Kokubu J., Sugano R., Ohtsuka M., Yokoyama N., Okano M., Tanabe T.

2023 Conference on Lasers and Electro-Optics, CLEO 2023  2023

　View Summary

Spectra are reconstructed by capturing wavelength-specific patterns of localized light in a photonic-crystal-waveguide. We show that real-time reconstruction at a wavelength resolution of 0.07 nm is possible by using low-rank approximation with singular-value-decomposition and regularized-least-squares.

Passive mode-locking without a saturable absorber using a coupled microresonator

Imamura R., Fujii S., Nakashima A., Tanabe T.

CLEO: Fundamental Science, CLEO:FS 2023  2023

　View Summary

Mode-locking usually requires saturable absorption or active modulation to trigger and build short pulses. We show through calculations that self-starting mode-locking may be achieved simply by coupling active and passive microresonators without a saturable absorber.

• Access to Document (DOI)

Passive mode-locking without a saturable absorber using a coupled microresonator

Imamura R., Fujii S., Nakashima A., Tanabe T.

CLEO: Applications and Technology, CLEO:A and T 2023  2023

　View Summary

Mode-locking usually requires saturable absorption or active modulation to trigger and build short pulses. We show through calculations that self-starting mode-locking may be achieved simply by coupling active and passive microresonators without a saturable absorber.

• Access to Document (DOI)

Passive mode-locking without a saturable absorber using a coupled microresonator

Imamura R., Fujii S., Nakashima A., Tanabe T.

CLEO: Science and Innovations, CLEO:S and I 2023  2023

　View Summary

Mode-locking usually requires saturable absorption or active modulation to trigger and build short pulses. We show through calculations that self-starting mode-locking may be achieved simply by coupling active and passive microresonators without a saturable absorber.

• Access to Document (DOI)

Passive mode-locking without a saturable absorber using a coupled microresonator

Imamura R., Fujii S., Nakashima A., Tanabe T.

2023 Conference on Lasers and Electro-Optics, CLEO 2023  2023

　View Summary

Mode-locking usually requires saturable absorption or active modulation to trigger and build short pulses. We show through calculations that self-starting mode-locking may be achieved simply by coupling active and passive microresonators without a saturable absorber.

Mode-locking System of Coupled Microcavities with Gain and Nonlinear Loss

Imamura R., Fujii S., Nakashima A., Tanabe T.

2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023  2023

　View Summary

Ultrahigh repetition rate lasers are vital light sources, and a mode-locked laser with whispering-gallery-mode (WGM) microresonators would provide a cost-effective on-chip solution. We have already reported numerically on the mode-locking in an erbium (Er) ion-doped resonator that was coated with polymer-dispersed carbon nanotubes (CNTs) [1]. Although mode-locking is possible, the required Q is still high, so the experiment remains challenging. In this work, we show that a coupled microresonator system with a gain resonator coupled to a nonlinear loss resonator will solve this problem. It is based on the idea of employing the Q revival of the gain cavity when the loss is increased at the cavity with additional loss, which is known to exist in the vicinity of the exceptional point [2].

• Access to Document (DOI)

Field Demonstration of Multi-Wavelength Optical Transmission with Microresonator Frequency Combs

Tanikawa K., Fujii S., Kogure S., Tanaka S., Tasaka S., Wada K., Kumazaki H., Kawanishi S., Tanabe T.

2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023  2023

　View Summary

Data traffic has been increasing with the spread of the internet. Therefore, a network that connects data centers and metropolitan areas requires a high-capacity, low-latency, and low-power-consumption optical communication system [1]. Since microresonator-based optical frequency combs (i.e., microcombs) have many longitudinal modes, they are expected to be applied to wavelength division multiplexing (WDM) communications [2,3]. We describe a field demonstration of a multi-wavelength optical transmission with a soliton microcomb. We employed intensity modulation and direct detection (IM-DD) for a simple and low-latency communication system [3]. We also used a magnesium fluoride (MgF2) microresonator because it has a small free spectral range (FSR) for efficient bandwidth use. Although sophisticated experiments have already been reported in the laboratory, we believe that our demonstration using a commercially installed optical fiber in a metropolitan area is a significant step towards the practical use of a microresonator system.

• Access to Document (DOI)

Field Demonstration of Low-Latency Massively Parallel Communication with Microresonator Frequency Comb

Tanikawa K., Fujii S., Tanaka S., Tasaka S., Wada K., Kogure S., Kumazaki H., Kawanishi S., Tanabe T.

CLEO: Science and Innovations, CLEO:S and I 2023  2023

　View Summary

We demonstrated low-latency optical transmission with a microresonator frequency comb using a 9-km optical fiber in a metropolitan area. The delay time of the entire system, excluding the transmission fiber, was only 3.1 μs.

• Access to Document (DOI)

Carbon Nanotubes Coupled with Silica Toroid Microcavities as Emitters for Silicon-Integrated Photonics

Tokunaga R., Kinoshita K., Imamura R., Nagashima K., Imafuku R., Nakagawa K., Tanabe T., Maki H.

ACS Applied Nano Materials 5 ( 10 ) 14328 - 14335 2022.10

　View Summary

A light source based on single-walled carbon nanotubes (SWNTs) is one of the promising candidates for a microsized light source on a silicon chip at telecommunication wavelengths in optical communications and optical interconnects. However, SWNT-based light emitters possess the disadvantage of having a very broad emission spectrum. Here, we present an ultranarrow-linewidth photoluminescence (PL) emitter based on a silica toroid resonator, along with SWNTs, on a silicon chip. We simultaneously managed both excitation and emission lights at telecommunication wavelengths on a silicon chip by employing a very simple in-line configuration consisting of a toroid resonator and a tapered fiber for light input and output. Owing to the extremely high Q factor of our silica toroid resonator, we obtained an ultrahigh Q factor (∼2.1 × 104) of C-band PL emission. We also demonstrated strong PL emission under laterally polarized excitation conditions owing to the strong coupling to the toroid resonator, and laterally polarized PL emission can be selectively generated independently of the excitation polarization direction. This SWNT-based PL emitter based on a simple system with a silica toroid resonator can open routes to highly integrated photonics and optoelectronics on silicon-based platforms.

• Access to Document (DOI)

Deterministic generation of a perfect soliton crystal microcomb with a saturable absorber

Nakashima A., Fujii S., Imamura R., Nagashima K., Tanabe T.

Optics Letters 47 ( 6 ) 1458 - 1461 2022.03

ISSN  01469592

　View Summary

We numerically investigate the deterministic generation of a perfect soliton crystal (PSC) in an optical microresonator functionalized with a saturable absorber (SA). The SAallows the direct formation of a PSC from an initial, periodic Turing roll. It prevents passage through a chaotic state, which induces a stochastic nature with regard to the number of generated dissipativeKerr solitons.We showthat PSCs form deterministically, and the number is controlled by adjusting the input power and SA parameter. Our work provides a simple approach for obtaining a stable PSC that offers an ultrahigh repetition rate and a high comb output power.

• Access to Document (DOI)

Dissipative Kerr soliton microcombs for FEC-free optical communications over 100 channels

Fujii S., Tanaka S., Ohtsuka T., Kogure S., Wada K., Kumazaki H., Tasaka S., Hashimoto Y., Kobayashi Y., Araki T., Furusawa K., Sekine N., Kawanishi S., Tanabe T.

Optics Express 30 ( 2 ) 1351 - 1364 2022.01

　View Summary

The demand for high-speed and highly efficient optical communication techniques has been rapidly growing due to the ever-increasing volume of data traffic. As well as the digital coherent communication used for core and metro networks, intensity modulation and direct detection (IM-DD) are still promising schemes in intra/inter data centers thanks to their low latency, high reliability, and good cost performance. In this work, we study a microresonator-based frequency comb as a potential light source for future IM-DD optical systems where applications may include replacing individual stabilized lasers with a continuous laser driven microresonator. Regarding comb line powers and spectral intervals, we compare a modulation instability comb and a soliton microcomb and provide a quantitative analysis with regard to telecom applications. Our experimental demonstration achieved a forward error correction (FEC) free operation of bit-error rate (BER) <10−9 with a 1.45 Tbps capacity using a total of 145 lines over the entire C-band and revealed the possibility of soliton microcomb-based ultra-dense wavelength division multiplexing (WDM) with a simple, cost-effective IM-DD scheme, with a view to future practical use in data centers.

• Access to Document (DOI)

Theoretical approach on the critical depth of cut of single crystal MgF<inf>2</inf> and application to a microcavity

Hayama Y., Fujii S., Tanabe T., Kakinuma Y.

Precision Engineering 73   234 - 243 2022.01

ISSN  01416359

　View Summary

Optical microcavity, which can localize light at a certain spot for a short period of time, has a wide range of applications, such as optical signal processing and optical frequency combs. Single crystal CaF2 has excellent optical properties and many research on the manufacturing process to create a microcavity has been done. However, due to its unstable thermal conditions, stable oscillation of Kerr comb could not be done. Single crystal MgF2, which also has excellent optical properties, has stable thermal conditions suitable to create a microcavity. Like CaF2, MgF2 microcavity can only be manufactured by ultra-precision cylindrical turning, yet its appropriate processing conditions is not known. In this study, a method to derive the critical depth of cut theoretically in ductile mode machining was proposed in consideration of specific cutting energy, mechanical properties and slip system of workpiece, and tool geometry. The critical depth of cut calculated by the proposed method roughly agreed with the experimental value on the MgF2 plane. Unlike CaF2, MgF2 has an optical anisotropy; therefore, in order to create a microcavity where the refractive angle is constant, the resonance part needs to be made on a cylinder with (001) plane as end face. Therefore, a microcavity was fabricated according to the critical depth of cut on a cylinder with (001) as end face derived from the proposed method, and the surface integrity was evaluated from the viewpoint of microcavity performance.

• Access to Document (DOI)

Deterministic Generation of Perfect Soliton Crystal Assisted by Saturable Absorption

Nakashima A., Fujii S., Imamura R., Nagashima K., Tanabe T.

2022 Conference on Lasers and Electro-Optics, CLEO 2022 - Proceedings  2022

　View Summary

We found that we can deterministically generate a perfect soliton crystal by incorporating a saturable absorber in a microresonator. The crystal is generated directly from the initial Turing rolls without passing through chaos.

Deterministic Generation of Perfect Soliton Crystal Assisted by Saturable Absorption

Nakashima A., Fujii S., Imamura R., Nagashima K., Tanabe T.

Optics InfoBase Conference Papers  2022

　View Summary

We found that we can deterministically generate a perfect soliton crystal by incorporating a saturable absorber in a microresonator. The crystal is generated directly from the initial Turing rolls without passing through chaos.

Active Thermal Tuning of a Soliton Frequency Comb in a Crystalline Optical Microresonator

Fujii S., Wada K., Kogure S., Kumazaki H., Tanabe T.

Optics InfoBase Conference Papers  2022

　View Summary

We report the thermal tuning of a Kerr soliton frequency comb in an ultrahigh-Q magnesium fluoride crystalline microresonator yielding broad pump frequency tuning of up to ~ 50 GHz and a repetition rate of ~ 6 MHz.

Active Thermal Tuning of a Soliton Frequency Comb in a Crystalline Optical Microresonator

Fujii S., Wada K., Kogure S., Kumazaki H., Tanabe T.

2022 Conference on Lasers and Electro-Optics, CLEO 2022 - Proceedings  2022

　View Summary

We report the thermal tuning of a Kerr soliton frequency comb in an ultrahigh-Q magnesium fluoride crystalline microresonator yielding broad pump frequency tuning of up to ~ 50 GHz and a repetition rate of ~ 6 MHz.

Effect of detuning on noise characteristics in a microcomb-based light source

Kogure S., Fujii S., Kumazaki H., Sota S., Hashimoto Y., Kobayashi Y., Araki T., Tanabe T.

2022 Conference on Lasers and Electro-Optics Pacific Rim, CLEO-PR 2022 - Proceedings  2022

　View Summary

We investigated the pump effective detuning dependence of noise and linewidth characteristics of modulation instability combs. Modulation instability combs are useful for applications if the detuning is smaller than several times the resonace linewidth.

• Access to Document (DOI)

Stability and mutual coherence measurement of a Raman microcomb in a silica WGM microresonator

Sugawara S., Fujii S., Sota S., Tanabe T.

Optics InfoBase Conference Papers  2022

　View Summary

We investigated the stability, longitudinal spacing, and mutual coherence of a generated Raman microcomb and found that we can obtain a highly stable and coherent Raman microcomb even without a four-wave mixing process.

Stability and mutual coherence measurement of a Raman microcomb in a silica WGM microresonator

Sugawara S., Fujii S., Sota S., Tanabe T.

2022 Conference on Lasers and Electro-Optics, CLEO 2022 - Proceedings  2022

　View Summary

We investigated the stability, longitudinal spacing, and mutual coherence of a generated Raman microcomb and found that we can obtain a highly stable and coherent Raman microcomb even without a four-wave mixing process.

Saturable Absorption of CNT and Fabrication of Erbium-doped Microresonator for On-chip Mode-locked Laser

Imamura R., Suzuki T.S.L.P., Ishida R., Fujii S., Set S.Y., Yamashita S., Tanabe T.

IEEJ Transactions on Electronics, Information and Systems 142 ( 3 ) 395 - 400 2022

ISSN  03854221

　View Summary

Mode-locked fiber lasers are gaining a lot of attention in the industry because of their excellent performance while being relatively inexpensive. Although fiber ring is robust and has been widely used, it only achieves a repetition rate of several hundreds of MHz due to the long fiber needed to build the resonator. On the other hand, Whispering-Gallery-Mode (WGM) microresonators can achieve an extremely high repetition rate due to the smallness of the device. We explore the possibility of a passively mode-locked laser with CNTs as a saturable absorber and erbium-doped microresonator.

• Access to Document (DOI)

Multi-wavelength reconstruction in a compact (&lt; mm) high-resolution (&lt; 0.1 nm) random photonic crystal spectrometer

Kodama T., Sugano R., Hofs J., Ohtsuka M., Seki M., Yokoyama N., Okano M., Tanabe T.

Optics InfoBase Conference Papers  2022

　View Summary

We experimentally demonstrate the reconstruction of multiple wavelength light with an ultra-compact spectrometer. The spectrometer is based on a random photonic crystal and operates with a spectral resolution beyond the fabrication error.

Multi-wavelength reconstruction in a compact (&lt; mm) high-resolution (&lt; 0.1 nm) random photonic crystal spectrometer

Kodama T., Sugano R., Hofs J., Ohtsuka M., Seki M., Yokoyama N., Okano M., Tanabe T.

2022 Conference on Lasers and Electro-Optics, CLEO 2022 - Proceedings  2022

　View Summary

We experimentally demonstrate the reconstruction of multiple wavelength light with an ultra-compact spectrometer. The spectrometer is based on a random photonic crystal and operates with a spectral resolution beyond the fabrication error.

Mode-locked Operation in a Coupled Microresonator System with Gain and Nonlinear Loss

Imamura R., Tate Y., Nakashima A., Nagashima K., Fujii S., Tanabe T.

Optics InfoBase Conference Papers  2022

　View Summary

We numerically study the mode-locking behavior in a system in which an erbium-doped resonator (gain) is coupled to a carbon-nanotube functionalized resonator (nonlinear loss). We find that mode-locking is possible even with a small gain and relatively low Q by adjusting the coupling between two cavities.

• Access to Document (DOI)

Mode-locked Operation in a Coupled Microresonator System with Gain and Nonlinear Loss

Imamura R., Tate Y., Nakashima A., Nagashima K., Fujii S., Tanabe T.

2022 Conference on Lasers and Electro-Optics Pacific Rim, CLEO-PR 2022 - Proceedings  2022

　View Summary

We numerically study the mode-locking behavior in a system in which an erbium-doped resonator (gain) is coupled to a carbon-nanotube functionalized resonator (nonlinear loss). We find that mode-locking is possible even with a small gain and relatively low Q by adjusting the coupling between two cavities.

• Access to Document (DOI)

Low-cost photonic crystal spectrometer using up-conversion

Sugano R., Jin S., Hofs J., Yube K., Nagashima K., Kodama T., Tanabe T.

Optics InfoBase Conference Papers  2022

　View Summary

We used up-conversion to capture the localized light of a photonic crystal spectrometer with an inexpensive CMOS camera. We employed this data to detect a single wavelength using deep learning.

• Access to Document (DOI)

Low-cost photonic crystal spectrometer using up-conversion

Sugano R., Jin S., Hofs J., Yube K., Nagashima K., Kodama T., Tanabe T.

2022 Conference on Lasers and Electro-Optics Pacific Rim, CLEO-PR 2022 - Proceedings  2022

　View Summary

We used up-conversion to capture the localized light of a photonic crystal spectrometer with an inexpensive CMOS camera. We employed this data to detect a single wavelength using deep learning.

• Access to Document (DOI)

Frequency comb generation in a silicon nitride microring resonator fabricated by using hot-wire CVD method

Sota S., Handa K., Tanabe T., Uzawa Y., Furusawa K., Sekine N.

2022 Conference on Lasers and Electro-Optics, CLEO 2022 - Proceedings  2022

　View Summary

We report frequency comb generation in a silicon nitride (SiN) based microring resonator fabricated by the hot-wire chemical vapor deposition (HW-CVD) method with an intrinsic quality factor in excess of 5×105,.

Frequency comb generation in a silicon nitride microring resonator fabricated by using hot-wire CVD method

Sota S., Handa K., Tanabe T., Uzawa Y., Furusawa K., Sekine N.

Optics InfoBase Conference Papers  2022

　View Summary

We report frequency comb generation in a silicon nitride (SiN) based microring resonator fabricated by the hot-wire chemical vapor deposition (HW-CVD) method with an intrinsic quality factor in excess of 5×105

FEC-free optical data transmission with a chip-integrated microresonator frequency comb source

Kogure S., Ohtsuka T., Fujii S., Kumazaki H., Tanaka S., Hashimoto Y., Kobayashi Y., Araki T., Furusawa K., Sekine N., Tanabe T.

Optics InfoBase Conference Papers  2022

　View Summary

We investigated the feasibility of IM-DD communication in a microcomb. Turing pattern and soliton combs are ideal, though MI comb can transmit signals when the pump-detuning is well controlled and excessive noise is suppressed.

FEC-free optical data transmission with a chip-integrated microresonator frequency comb source

Kogure S., Ohtsuka T., Fujii S., Kumazaki H., Tanaka S., Hashimoto Y., Kobayashi Y., Araki T., Furusawa K., Sekine N., Tanabe T.

2022 Conference on Lasers and Electro-Optics, CLEO 2022 - Proceedings  2022

　View Summary

We investigated the feasibility of IM-DD communication in a microcomb. Turing pattern and soliton combs are ideal, though MI comb can transmit signals when the pump-detuning is well controlled and excessive noise is suppressed.

FEC-free dense WDM transmission with Kerr soliton microcombs in crystalline MgF<inf>2</inf> microresonators

Tanikawa K., Tasaka S., Fujii S., Tanaka S., Kumazaki H., Wada K., Kogure S., Kawanishi S., Tanabe T.

Optics InfoBase Conference Papers  2022

　View Summary

We demonstrated forward-error-correction (FEC)-free dense wavelength division multiplexing communication utilizing a Kerr soliton frequency comb generated from a high-Q crystalline microresonator with a 20-GHz free spectral range.

• Access to Document (DOI)

FEC-free dense WDM transmission with Kerr soliton microcombs in crystalline MgF<inf>2</inf> microresonators

Tanikawa K., Tasaka S., Fujii S., Tanaka S., Kumazaki H., Wada K., Kogure S., Kawanishi S., Tanabe T.

2022 Conference on Lasers and Electro-Optics Pacific Rim, CLEO-PR 2022 - Proceedings  2022

　View Summary

We demonstrated forward-error-correction (FEC)-free dense wavelength division multiplexing communication utilizing a Kerr soliton frequency comb generated from a high-Q crystalline microresonator with a 20-GHz free spectral range.

• Access to Document (DOI)

Experimental investigation of Raman comb formation and stability in a silica microrod resonator

Sugawara S., Fujii S., Kumazaki H., Shota S., Tanabe T.

Optics InfoBase Conference Papers  2022

　View Summary

We investigated the stability mechanism of a Raman comb by measuring RF beat noise and dispersion. Our measurements suggest that the Raman comb is stable even when only the stimulated Raman process is present.

Enhancing the wavelength resolution of a chirped photonic crystal waveguide based spectrometer by employing fabrication error

Tanabe T., Kodama T., Sugano R.

International Conference on Metamaterials, Photonic Crystals and Plasmonics    213 - 214 2022

　View Summary

The presence of fabrication errors often degrades the performance of nanophotonic devices. Fabrication errors in the photonic crystal waveguide often appear as the Anderson localization of light. We show that the random localization of light can enhance the resolution of a photonic crystal spectrometer by utilizing this localization information in advance of the measurement.

Effect of detuning on noise characteristics in a microcomb-based light source

Kogure S., Fujii S., Kumazaki H., Sota S., Hashimoto Y., Kobayashi Y., Araki T., Tanabe T.

Optics InfoBase Conference Papers  2022

　View Summary

We investigated the pump effective detuning dependence of noise and linewidth characteristics of modulation instability combs. Modulation instability combs are useful for applications if the detuning is smaller than several times the resonace linewidth.

• Access to Document (DOI)

Design of a passively mode-locking whispering-gallery-mode microlaser

Suzuki T.P.S.L., Nakashima A., Nagashima K., Ishida R., Imamura R., Fujii S., Set S.Y., Yamashita S., Tanabe T.

Journal of the Optical Society of America B: Optical Physics 38 ( 10 ) 3172 - 3178 2021.10

ISSN  07403224

　View Summary

Ultrahigh-repetition-rate lasers will become vital light sources for many future technologies; however, their realization is challenging because the cavity size must be minimized. Whispering-gallery-mode (WGM) microresonators are attractive for this purpose since they allow the strong light–matter interaction usually needed to enable mode locking. However, the optimum parameter ranges are entirely unknown since no experiments have yet been conducted. Here, we numerically investigate pulsed operation in a toroidal WGM microresonator with gain and saturable absorption (SA) to study the experimental feasibility. We show that dispersion is the key parameter for achieving passive mode locking in this system. Moreover, the design guideline provided in this work can apply to any small resonators with gain and SA and is not limited to a specific cavity system.

• Access to Document (DOI)

Design of a Passively Mode-locked Microlaser with an Er-doped Microcavity and Carbon Nanotubes

Imamura R., Nakashima A., Nagashima K., Prugger Suzuki T.S.L., Ishida R., Fujii S., Tanabe T.

2021 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2021  2021.06

　View Summary

Ultrahigh repetition rate lasers will become vital light sources for many technologies; however, they are difficult to realize because the cavity must be miniaturized. A mode-locked laser with whispering-gallery-mode (WGM) microresonators would provide a cost-effective on-chip solution that would allow us to demonstrate ultra-high repetition rate lasers. However, the required parameters, such as the cavity size, dispersion, minimum gain, and amount of saturable absorption (SA) loss, are unknown; we need to establish a clear guideline if we wish to discuss experimental feasibility and achieve mode locking (ML). Here, we report on a numerical investigation that clarified the optimum design parameters to achieve passive ML with a toroidal WGM microlaser.

• Access to Document (DOI)

Optical Data Transmission with a Dissipative Kerr Soliton in an Ultrahigh-Q MgF<inf>2</inf>Microresonator

Tanaka S., Fujii S., Wada K., Kumazaki H., Kogure S., Tasaka S., Ohtsuka T., Kawanishi S., Tanabe T.

2021 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2021  2021.06

　View Summary

Optical frequency combs based on microresonators (microcombs) have been actively researched since the first experimental achievement of soliton mode-locking. Soliton pulses (dissipative Kerr solitons; DKSs) possess high repetition rates ranging from tens to hundreds of GHz. Thanks to this feature, DKSs are expected to benefit a wide range of applications, such as optical communications. In particular, DKSs are highly suitable for wavelength division multiplexing (WDM) transmission, which exploits an individual comb line as an optical carrier, owing to its broad bandwidth and low-noise properties [1] , [2]. Although coherent transmissions are currently the mainstream of optical communication, transmissions employing the intensity-modulation direct-detection (IM-DD) method remain in use, e.g., in data centers [3]. The advantage of an IM-DD transmission is that it does not require complex digital signal processors, resulting in a low power consumption and a small-signal delay, both of which are key characteristics required in the Beyond-5G technology. The IM-DD method can be used in conjunction with microcombs to achieve high-speed transmission while maintaining these advantages.

• Access to Document (DOI)

Stable Formation of Multiple Solitons in an Optical Microresonator Assisted by Saturable Absorption

Nakashima A., Fujii S., Imamura R., Nagashima K., Tanabe T.

2021 Conference on Lasers and Electro-Optics, CLEO 2021 - Proceedings  2021.05

　View Summary

We numerically investigate soliton microcomb generation with a saturable absorption effect. We found that a cavity-integrated saturable absorber allows the formation of a much higher number of solitons than possible with a Kerr-only monolithic cavity.

Design of a passively mode-locked microlaser with an Er-doped microcavity and carbon nanotubes

Imamura R., Nakashima A., Nagashima K., Prugger Suzuki T.S.L., Ishida R., Fujii S., Tanabe T.

Optics InfoBase Conference Papers  2021

Comparison of microcomb-based light sources for optical data transmission

Kogure S., Ohtsuka T., Fujii S., Kumazaki H., Wada K., Hashimoto Y., Kobayashi Y., Araki T., Furusawa K., Sekine N., Tanabe T.

Optics InfoBase Conference Papers  2021

　View Summary

We performed a transmission experiment to compare microcomb states using a silicon nitride microresonator. A modulation instability comb with the correct amount of detuning can provide a light source almost comparable to a soliton comb.

Fabrication of dispersion engineered ultrahigh-Q crystalline optical microresonator for broad-bandwidth optical parametric oscillation

Fujii S., Wada K., Kakinuma Y., Tanabe T.

Proceedings of SPIE - The International Society for Optical Engineering 11672 2021

ISSN  0277786X

　View Summary

We demonstrate the all-precision-machining fabrication of ultrahigh-quality-factor (Q) crystalline optical microresonators. The obtained Q exceeds 100 million for both magnesium fluoride (MgF2) and calcium fluoride (CaF2) materials. This constitutes the highest Q factor obtained for whispering gallery mode crystalline microresonators fabricated solely by ultra-precision machining. We also achieve octave-wide optical parametric oscillation using an MgF2 resonator fabricated with a computer-controlled machining process. This method readily enables advanced dispersion engineering for optical parametric oscillation and makes it possible to explore microcavity nonlinear optics and quantum optics without the need for skilled manual polishing techniques.

• Access to Document (DOI)

Stable formation of multiple solitons in an optical microresonator assisted by saturable absorption

Nakashima A., Fujii S., Imamura R., Nagashima K., Tanabe T.

Optics InfoBase Conference Papers  2021

　View Summary

We numerically investigate soliton microcomb generation with a saturable absorption effect. We found that a cavity-integrated saturable absorber allows the formation of a much higher number of solitons than possible with a Kerr-only monolithic cavity.

Optical data transmission with a dissipative kerr soliton in an ultrahigh-Q MgF2 microresonator

Tanaka S., Fujii S., Wada K., Kumazaki H., Kogure S., Tasaka S., Ohtsuka T., Kawanishi S., Tanabe T.

Optics InfoBase Conference Papers  2021

Measurement of saturable absorption behavior of CNT/PDMS coated high-Q microcavity towards mode-locking of Er-doped laser

Imamura R., Nagashima K., Tanabe T.

International Conference on Metamaterials, Photonic Crystals and Plasmonics    198 - 199 2021

　View Summary

We developed a method for coating CNT/PDMS on a high- Q silica microcavity that allows us to obtain saturable absorption that is needed for building a microresonator based Er-doped mode-locked laser.

Saturable absorption by carbon nanotubes on silica microtoroids

Kumagai, Tsutaru, Hirota, Naoya, Sato, Katsuya, Namiki, Koki, Maki, Hideyuki, Tanabe, Takasumi

JOURNAL OF APPLIED PHYSICS 123 ( 23 ) 933 - 938 2018.06

Research paper (scientific journal),  ISSN  0021-8979

• Access to Document (DOI)

Suppression of optomechanical parametric oscillation in a toroid microcavity assisted by a Kerr comb

Suzuki, Ryo, Kato, Takumi, Kobatake, Tomoya, Tanabe, Takasumi

OPTICS EXPRESS 25 ( 23 ) 28806 - 28816 2017.11

Research paper (scientific journal),  ISSN  1094-4087

• Access to Document (DOI)

Chalcogenide photonic crystal fiber for ultraflat mid-infrared supercontinuum generation

Vyas, Sandeep, Tanabe, Takasumi, Tiwari, Manish, Singh, Ghanshyam

CHINESE OPTICS LETTERS 14 ( 12 ) 26322 - 26331 2016.12

Research paper (scientific journal),  ISSN  1671-7694

• Access to Document (DOI)

Kerr-induced controllable adiabatic frequency conversion in an ultrahigh Q silica toroid microcavity

Yoshiki, Wataru, Honda, Yoshihiro, Kobayashi, Misako, Tetsumoto, Tomohiro, Tanabe, Takasumi

OPTICS LETTERS 41 ( 23 ) 5482 - 5485 2016.12

Research paper (scientific journal),  ISSN  0146-9592

• Access to Document (DOI)

Broad bandwidth third-harmonic generation via four-wave mixing and stimulated Raman scattering in a microcavity

Chen-Jinnai, Akitoshi, Kato, Takumi, Fujii, Shun, Nagano, Takuma, Kobatake, Tomoya, Tanabe, Takasumi

OPTICS EXPRESS 24 ( 23 ) 26322 - 26331 2016.11

Research paper (scientific journal),  ISSN  1094-4087

• Access to Document (DOI)

Dispersion tailoring of a crystalline whispering gallery mode microcavity for a wide-spanning optical Kerr frequency comb

Nakagawa, Yosuke, Mizumoto, Yuta, Kato, Takumi, Kobatake, Tomoya, Itobe, Hiroki, Kakinuma, Yasuhiro, Tanabe, Takasumi

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS 33 ( 9 ) 1913 - 1920 2016.09

Research paper (scientific journal),  ISSN  0740-3224

• Access to Document (DOI)

Ultraflat broadband supercontinuum in highly nonlinear Ge11.5As24Se64.5 photonic crystal fibres

Vyas, Sandeep, Tanabe, Takasumi, Tiwari, Manish, Singh, Ghanshyam

UKRAINIAN JOURNAL OF PHYSICAL OPTICS 17 ( 3 ) 132 - 139 2016.09

Research paper (scientific journal),  ISSN  1609-1833

Hysteresis behavior of Kerr frequency comb generation in a high-quality-factor whispering-gallery-mode microcavity

Kato, Takumi, Chen-Jinnai, Akitoshi, Nagano, Takuma, Kobatake, Tomoya, Suzuki, Ryo, Yoshiki, Wataru, Tanabe, Takasumi

JAPANESE JOURNAL OF APPLIED PHYSICS 55 ( 7 ) 26322 - 26331 2016.07

Research paper (scientific journal),  ISSN  0021-4922

• Access to Document (DOI)

Compact resonant electro-optic modulator using randomness of a photonic crystal waveguide

Ooka, Yuta, Daud, Nurul Ashikin Binti, Tetsumoto, Tomohiro, Tanabe, Takasumi

OPTICS EXPRESS 24 ( 10 ) 1913 - 1920 2016.05

Research paper (scientific journal),  ISSN  1094-4087

• Access to Document (DOI)

Thermal and quantum phase slips in niobium-nitride nanowires based on suspended carbon nanotubes

Masuda, Kohei, Moriyama, Satoshi, Morita, Yoshifumi, Komatsu, Katsuyoshi, Takagi, Tasuku, Hashimoto, Takayuki, Miki, Norihisa, Tanabe, Takasumi, Maki, Hideyuki

APPLIED PHYSICS LETTERS 108 ( 22 )  2016.05

Research paper (scientific journal),  ISSN  0003-6951

• Access to Document (DOI)

Thermal Effects on Kerr Comb Generation in a CaF2 Whispering-Gallery Mode Microcavity

Kobatake, Tomoya, Kato, Takumi, Itobe, Hiroki, Nakagawa, Yosuke, Tanabe, Takasumi

IEEE PHOTONICS JOURNAL 8 ( 2 )  2016.04

Research paper (scientific journal),  ISSN  1943-0655

• Access to Document (DOI)

NaCl ion detection using a silica toroid microcavity

Nishimura, Jiro, Kobayashi, Misako, Saito, Ryusuke, Tanabe, Takasumi

APPLIED OPTICS 54 ( 20 ) 6391 - 6396 2015.07

Research paper (scientific journal),  ISSN  1559-128X

• Access to Document (DOI)

CMOS compatible high-Q photonic crystal nanocavity fabricated with photolithography on silicon photonic platform

Ooka, Yuta, Tetsumoto, Tomohiro, Fushimi, Akihiro, Yoshiki, Wataru, Tanabe, Takasumi

SCIENTIFIC REPORTS 5   19382 - 19387 2015.06

Research paper (scientific journal),  ISSN  2045-2322

• Access to Document (DOI)

Octagonal toroid microcavity for mechanically robust optical coupling

Suzuki, Ryo, Kato, Takumi, Tetsumoto, Tomohiro, Tanabe, Takasumi

AIP ADVANCES 5 ( 5 ) 172 - 181 2015.05

Research paper (scientific journal),  ISSN  2158-3226

• Access to Document (DOI)

Experimental study of crystal anisotropy based on ultra-precision cylindrical turning of single-crystal calcium fluoride

Azami, Shunya, Kudo, Hiroshi, Mizumoto, Yuta, Tanabe, Takasumi, Yan, Jiwang, Kakinuma, Yasuhiro

PRECISION ENGINEERING-JOURNAL OF THE INTERNATIONAL SOCIETIES FOR PRECISION ENGINEERING AND NANOTECHNOLOGY 40   172 - 181 2015.04

Research paper (scientific journal),  ISSN  0141-6359

• Access to Document (DOI)

Evaluation of subsurface damage caused by ultra-precision turning in fabrication of CaF2 optical micro resonator

Kakinuma, Yasuhiro, Azami, Shunya, Tanabe, Takasumi

CIRP ANNALS-MANUFACTURING TECHNOLOGY 64 ( 1 ) 117 - 120 2015

Research paper (scientific journal),  ISSN  0007-8506

• Access to Document (DOI)

All-optical logic gate operating with single wavelength

Fushimi, Akihiro, Tanabe, Takasumi

OPTICS EXPRESS 22 ( 4 ) 4466 - 4479 2014.02

Research paper (scientific journal),  ISSN  1094-4087

• Access to Document (DOI)

Whispering gallery modes in hexagonal microcavities

Kudo, Hiroshi, Suzuki, Ryo, Tanabe, Takasumi

PHYSICAL REVIEW A 88 ( 2 )  2013.08

Research paper (scientific journal),  ISSN  1050-2947

• Access to Document (DOI)

Fabrication of whispering gallery mode cavity using crystal growth

Kudo, Hiroshi, Ogawa, Yohei, Kato, Takumi, Yokoo, Atsushi, Tanabe, Takasumi

APPLIED PHYSICS LETTERS 102 ( 21 )  2013.05

Research paper (scientific journal),  ISSN  0003-6951

• Access to Document (DOI)

Analysis of bistable memory in silica toroid microcavity

Yoshiki, Wataru, Tanabe, Takasumi

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS 29 ( 12 ) 3335 - 3343 2012.12

Research paper (scientific journal),  ISSN  0740-3224

Analysis of bistable memory in silica toroid microcavity

W. Yoshiki and T. Tanabe

J. Opt. Soc. Amer. B 29 ( 12 ) 3335-3343 2012

Research paper (scientific journal), Joint Work, Accepted

Octagonal silica toroidal microcavity for controlled optical coupling

T. Kato, W. Yoshiki, R. Suzuki, and T. Tanabe

Appl. Phys. Lett. 101   121101 2012

Research paper (scientific journal), Joint Work, Accepted

Ultrahigh-Q Nanocavities Written with a Nanoprobe

Yokoo, Atsushi, Tanabe, Takasumi, Kuramochi, Eiichi, Notomi, Masaya

NANO LETTERS 11 ( 9 ) 3634 - 3642 2011.09

Research paper (scientific journal),  ISSN  1530-6984

• Access to Document (DOI)

Low-power nanophotonic devices based on photonic crystals towards dense photonic network on chip

Notomi, M., Shinya, A., Nozaki, K., Tanabe, T., Matsuo, S., Kuramochi, E., Sato, T., Taniyama, H., Sumikura, H.

IET CIRCUITS DEVICES &amp; SYSTEMS 5 ( 2 ) 84 - 93 2011.03

Research paper (scientific journal),  ISSN  1751-858X

• Access to Document (DOI)

Low power nanophotonic devices based on photonic crystals towards dense photonic network on chip

M. Notomi, A. Shinya, K. Nozaki, T. Tanabe, S. Matsuo, E. Kuramochi, T. Sato, H. Taniyama and H. Sumikura

IET Circuits, Devices & Systems 5 ( 2 ) 84-93 2011

Research paper (scientific journal), Joint Work, Accepted

Ultrahigh-Q nanocavities written with a nanoprobe

A. Yokoo, T. Tanabe, E. Kuramochi, and M. Notomi

Nano Letters 11   3634-3642 2011

Research paper (scientific journal), Joint Work, Accepted

Sub-femtojoule all-optical switching using a photonic-crystal nanocavity

Nozaki, Kengo, Tanabe, Takasumi, Shinya, Akihiko, Matsuo, Shinji, Sato, Tomonari, Taniyama, Hideaki, Notomi, Masaya

NATURE PHOTONICS 4 ( 7 ) 477 - 483 2010.07

Research paper (scientific journal),  ISSN  1749-4885

• Access to Document (DOI)

Strong optomechanical interaction in a bilayer photonic crystal

Roh, Young-Geun, Tanabe, Takasumi, Shinya, Akihiko, Taniyama, Hideaki, Kuramochi, Eiichi, Matsuo, Shinji, Sato, Tomonari, Notomi, Masaya

PHYSICAL REVIEW B 81 ( 12 ) 477 - 483 2010.03

Research paper (scientific journal),  ISSN  1098-0121

• Access to Document (DOI)

Strong optomechanical interaction in a bilayer photonic crystal

Roh, Young-Geun, Tanabe, Takasumi, Shinya, Akihiko, Taniyama, Hideaki, Kuramochi, Eiichi, Matsuo, Shinji, Sato, Tomonari, Notomi, Masaya

PHYSICAL REVIEW B 81 ( 12 ) 477 - 483 2010.03

Research paper (scientific journal),  ISSN  1098-0121

• Access to Document (DOI)

All-silicon sub-Gb/s telecom detector with low dark current and high quantum efficiency on chip

T. Tanabe, H. Sumikura, H. Taniyama, A. Shinya, and M. Notomi

Appl. Phys. Lett. 96   101103 2010

Research paper (scientific journal), Joint Work, Accepted

Strong optomechanical interaction in a bilayer photonic crystal

Y.-G. Roh, T. Tanabe, A. Shinya, H. Taniyama, E. Kuramochi, S. Matsuo, T. Sato, and M. Notomi

Phys. Rev. B 81   121101(R) 2010

Research paper (scientific journal), Joint Work, Accepted

Sub-femtojoule all-optical switching using a photonic crystal nanocavity

K. Nozaki, T. Tanabe, A. Shinya, S. Matsuo, T. Sato, H. Taniyama, and M. Notomi

Nature Photonics 4   477-483 2010

Research paper (scientific journal), Joint Work, Accepted

Ultrahigh-Q one-dimensional photonic crystal nanocavities with modulated mode-gap barriers on SiO2 claddings and on air claddings

E. Kuramochi, H. Taniyama, T. Tanabe, K. Kawasaki, Y.-G. Roh, and M. Notomi

Opt. Express 18   15859-15869 2010

Research paper (scientific journal), Joint Work, Accepted

Electro-optic adiabatic wavelength shifting and Q switching demonstrated using a p-i-n integrated photonic crystal nanocavity

T. Tanabe, E. Kuramochi, H. Taniyama, and M. Notomi

Opt. Lett. 35   3895-3897 2010

Research paper (scientific journal), Joint Work, Accepted

Cavity-QED assisted attraction between a cavity mode and an exciton mode in a planar photonic-crystal cavity

T. Tawara, H. Kamada, T. Tanabe, T. Sogawa, H. Okamoto, P. Yao, P. Pathak, and S. Hughes

Opt. Express 18   2719-2728 2010

Research paper (scientific journal), Joint Work, Accepted

Dynamic Release of Trapped Light from an Ultrahigh-Q Nanocavity via Adiabatic Frequency Tuning

Tanabe, Takasumi, Notomi, Masaya, Taniyama, Hideaki, Kuramochi, Eiichi

PHYSICAL REVIEW LETTERS 102 ( 4 ) 2719 - 2728 2009.01

Research paper (scientific journal),  ISSN  0031-9007

• Access to Document (DOI)

Short pulse generation by adiabatic tuning of light

T. Tanabe, M. Notomi, H. Taniyama, and E. Kuramochi

Opt. & Phot. News 20   41 2009

Research paper (scientific journal), Joint Work, Accepted

Dynamic release of trapped light from an ultrahigh-Q nanocavity via adiabatic frequency tuning

T. Tanabe, M. Notomi, H. Taniyama, and E. Kuramochi

Phys. Rev. Lett. 102   043907 2009

Research paper (scientific journal), Joint Work, Accepted

Extremely low power optical bistability in silicon demonstrated using 1D photonic crystal nanocavity

L.-D. Haret, T. Tanabe, E. Kuramochi, and M. Notomi,

Opt. Express 17   21108-21117 2009

Research paper (scientific journal), Joint Work, Accepted

Low power and fast electro-optic silicon modulator with lateral p-i-n embedded photonic crystal nanocavity

T. Tanabe, K. Nishiguchi, E. Kuramochi, and M. Notomi

Opt. Express 27   22505-22513 2009

Research paper (scientific journal), Joint Work, Accepted

Carrier diffusion and recombination in photonic crystal nanocavity optical switches

Tanabe, Takasumi, Taniyama, Hideaki, Notomi, Masaya

JOURNAL OF LIGHTWAVE TECHNOLOGY 26 ( 9-12 ) 1396 - 1403 2008.01

Research paper (scientific journal),  ISSN  0733-8724

• Access to Document (DOI)

Large-scale arrays of ultrahigh-Q coupled nanocavities

M. Notomi, E. Kuramochi, and T. Tanabe

Nature Photonics 2   741-747 2008

Research paper (scientific journal), Joint Work, Accepted

Photonic Crystal Nanocavities with Extremely Long Photon Lifetimes and Their Applications

T. Tanabe, E. Kuramochi, A. Shinya, H. Taniyama, and M. Notomi

The Review of Laser Engineering 36   1310-1313 2008

Research paper (scientific journal), Joint Work, Accepted

Quality factor control and lasing characteristics of InAs/InGaAs quantum dots embedded in photonic-crystal nanocavities

T. Tawara, H. Kamada, Y-H Zhang, T. Tanabe, N. I. Cade, D. Ding, S. R. Johnson, H. Gotoh, E. Kuramochi, M. Notomi, and T. Sogawa

Opt. Express 16   5199-5205 2008

Research paper (scientific journal), Joint Work, Accepted

Carrier diffusion and recombination in photonic crystal nanocavity optical switches

T. Tanabe, H. Taniyama, and M. Notomi

IEEE/OSA J. Lightwave Technol. 26   1396-1403 2008

Research paper (scientific journal), Single Work, Accepted

On-chip all-optical switching and memory by silicon photonic crsytal nanocavities

M. Notomi, T. Tanabe, A. Shinya, E. Kuramochi, and H. Taniyama

Advances in Optical Technologies 2008   568936 2008

Research paper (scientific journal), Joint Work, Accepted

Trapping and delaying light with an ultrahigh-Q photonic crystal nanocavity

T. Tanabe, E. Kuramochi, H. Taniyama, and M. Notomi

NTT Technical Review 6 ( 8 )  2008

Research paper (bulletin of university, research institution), Joint Work, Accepted

Ultrahigh-Q two-dimentional photonic crystal slab nanocavities in very thin barriers

E. Kuramochi, H. Taniyama, T. Tanabe, A. Shinya, and M. Notomi

Appl. Phys. Lett. 93   111112 2008

Research paper (scientific journal), Joint Work, Accepted

All-optical on-chip bit memory based on ultra high Q InGaAsP photonic crystal

A. Shinya, S. Matsuo, Yosia, T. Tanabe, E. Kuramochi, T. Sato, T. Kakitsuka, and M. Notomi

Opt. Express 16   19382-19387 2008

Research paper (scientific journal), Joint Work, Accepted

Measurement of ultra-high-Q photonic crystal nanocavity using single-sideband frequency modulator

Tanabe, T., Notomi, M., Kuramochi, E.

ELECTRONICS LETTERS 43 ( 3 ) 187 - 188 2007.02

Research paper (scientific journal),  ISSN  0013-5194

• Access to Document (DOI)

Trapping and delaying photons for one nanosecond in an ultra-small high-Q photonic-crystal nanocavity

T. Tanabe, M. Notomi, E. Kuramochi, A. Shinya, H. Taniyama

Nature Photonics 1 ( 1 ) 49-52 2007.01

Research paper (scientific journal), Joint Work

Nonlinear and adiabatic control of high-Q photonic crystal nanocavities

M. Notomi, T. Tanabe, A. Shinya, E. Kuramochi, H. Taniyama, S. Mitsugi, and M. Morita

Opt. Express 15   17458-17481 2007

Research paper (scientific journal), Joint Work, Accepted

Fast all-optical switching using ion-implanted silicon photonic crystal nanocavities

T. Tanabe, K. Nishiguchi, A. Shinya, E. Kuramochi, H. Inokawa, M. Notomi, K. Yamada, T. Tsuchizawa, T. Watanabe, H. Fukuda, H. Shinojima, and S. Itabashi

Appl. Phys. Lett. 90   031115 2007

Research paper (scientific journal), Single Work

Measurement of an ultra-high-Q photonic crystal nanocavity using a single-side-band frequency modulator

T. Tanabe, M. Notomi and E. Kuramochi

Electron. Lett. 43   187-188 2007

Research paper (scientific journal), Single Work

Large pulse delay and small group velocity achieved using ultrahigh-Q photonic crystal nanocavities

T. Tanabe, M. Notomi, E. Kuramochi, and H. Taniyama

Opt. Express 15   7826-7839 2007

Research paper (scientific journal), Joint Work

Single point defect photonic crystal nanocavity with ultrahigh quality factor achieved by using hexapole mode

T. Tanabe, A. Shinya, E. Kuramochi, S. Kondo, H. Taniyama, and M. Notomi

Appl. Phys. Lett. 91   021110 2007

Research paper (scientific journal), Joint Work

Caging light with a photonic crystal nanocavity

T. Tanabe, E. Kuramochi, H. Taniyama, and M. Notomi

New Breeze 19   20-21 2007

Research paper (bulletin of university, research institution), Single Work

Highly Selective ZEP/AlGaAs Etching for Photonic Crystal Structures Using Cl2/HI/Xe Mixed Plasma

T. Tawara, T. Ito, T. Tanabe, K. Tateno, E. Kuramochi, M. Notomi and H. Nakano,

Jpn. J. Appl. Phys. 45   L917-L919 2006

Research paper (scientific journal), Joint Work

Ultrahigh-Q photonic crystal nanocavities realized by the local width modulation of a line defect

E. Kuramochi, M. Notomi, S. Mitsugi, A. Shinya, T. Tanabe, T. Watanabe

Appl. Phys. Lett. 88   041112 2006

Research paper (scientific journal), Single Work

All-optical flip-flop circuit composed of coupled two-port resonant tunneling filter in two-dimensional photonic crystal slab

A. Shinya, S. Mitsugi, T. Tanabe, M. Notomi, I. Yokohama, H. Takara, S. Kawanishi

Opt. Express 14   1230-1235 2006

Research paper (conference, symposium, etc.), Joint Work, Accepted

Open-loop and closed-loop control of dissociative ionization of ethanol in intense laser fields

H. Yazawa, T. Tanabe, T. Okamoto, M. Yamanaka, F. Kannari, R. Itakura, and K. Yamanouchi

J. Chem. Phys. 124   20314 2006

Research paper (scientific journal), Joint Work

Fast bistable all-optical switch and memory on a silicon photonic crystal on-chip

Tanabe, T, Notomi, M, Mitsugi, S, Shinya, A, Kuramochi, E

OPTICS LETTERS 30 ( 19 ) 2575 - 2577 2005.10

Research paper (scientific journal),  ISSN  0146-9592

All-optical switches and memories fabricated on a silicon chip using photonic crystal nanocavities

T. Tanabe, M. Notomi, A. Shinya, S. Mitsugi, and E. Kuramochi

Opt. & Phot. News 16   35 2005

Research paper (scientific journal), Joint Work, Accepted

Influence of spatiotemporal coupling induced by ultrashort laser pulse shaper on the focused beam profile

T. Tanabe, F. Kannari, F. Korte, J. Koch, and B. Chichkov

Appl. Opt. 44   1092-1098 2005

Research paper (scientific journal), Joint Work, Accepted

Optical bistable switching action of Si high-Q photonic-crystal nanocavities

M. Notomi, A. Shinya, S. Mitsugi, G. Kira, E. Kuramochi, and T. Tanabe

Opt. Express 13   2678-2687 2005

Research paper (scientific journal), Joint Work, Accepted

Fast bistable all-optical switch and memory on silicon photonic crystal on-chip

T. Tanabe, M. Notomi, A. Shinya, S. Mitsugi, and E. Kuramochi

Opt. Lett. 30 ( 19 ) 2575-2577 2005

Research paper (scientific journal), Joint Work, Accepted

All-optical switches and memories fabricated on a silicon chip using photonic crystal nanocavities

T. Tanabe, M. Notomi, A. Shinya, S. Mitsugi, and E. Kuramochi

Appl. Phys. Lett. 87   151112 2005

Research paper (scientific journal), Joint Work, Accepted

Compensation for a transfer function of a regenerative amplifier to generate accurately shaped ultrashort pulses in both the amplitude and phase

Tanabe, T, Yamanaka, M, Okamoto, T, Kannari, F

IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS 10 ( 1 ) 221 - 228 2004.01

Research paper (scientific journal),  ISSN  1077-260X

• Access to Document (DOI)

Selective excitation between two-photon and three-photon fluorescence with engineered cost functions

J. Chen, H. Kawano, Y. Nabekawa, H. Mizuno, A. Miyawaki, T. Tanabe, F. Kannari, and K. Midorikawa

Opt. Express 12   3408-3414 2004

Research paper (scientific journal), Joint Work, Accepted

Compensation for a transfer function of a regenerative amplifier to generate accurately shaped ultrashort pulses in both the amplitude and phase

T. Tanabe, M. Yamanaka, T. Okamoto, and F. Kannari

IEEE J. Sel. Top. Quantum Electron. 10   221-228 2004

Research paper (scientific journal), Joint Work, Accepted

Feedback control for accurate shaping of ultrashort optical pulses prior to chirped pulse amplification

T. Tanabe, T. Okamoto, M. Yamanaka, and F. Kannari

Jpn. J. Appl. Phys. 42   1366-1375 2004

Research paper (scientific journal), Joint Work, Accepted

Spectrum-holographic formation of fine etching patterns on a silicon surface with pulse-shaped femtosecond laser pulses

Tanabe, T, Okamoto, T, Kannari, F

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES &amp; REVIEW PAPERS 42 ( 9A ) 5594 - 5597 2003.09

Research paper (scientific journal),  ISSN  0021-4922

• Access to Document (DOI)

Dissociative ionization of ethanol in chirped intense laser fields

Itakura, R, Yamanouchi, K, Tanabe, T, Okamoto, T, Kannari, F

JOURNAL OF CHEMICAL PHYSICS 119 ( 8 ) 4179 - 4186 2003.08

Research paper (scientific journal),  ISSN  0021-9606

• Access to Document (DOI)

Fiber delivery of ultrashort optical pulses pre-shaped on the basis of a backward propagation solver

T. Yamazaki, T. Tanabe, F. Kannari, Y. Shida, and S. Fushimi

Jpn. J. Appl. Phys. 42   7313-7317 2003

Research paper (scientific journal), Joint Work, Accepted

Dissociative ionization of ethanol in chirped intense laser fields

R. Itakura, K. Yamanouchi, T. Tanabe, T. Okamoto, and F. Kannari

J. Chem. Phys. 119   4179-4186 2003

Research paper (scientific journal), Joint Work

Spectrum-holographic formation of fine etching patterns on a silicon surface with pulse-shaped femtosecond laser pulses

T. Tanabe, T. Okamoto, and F. Kannari

Jpn. J. Appl. Phys. 42   5594-5597 2003

Research paper (scientific journal), Joint Work, Accepted

Adaptive pulse shaping of femtosecond laser pulses in amplitude and phase through a single-mode fiber by referring to frequency-resolved optical gating patterns

M. Sato, M. Suzuki, M. Shiozawa, T. Tanabe, K. Ohno, and F. Kannari

Japanese Journal of Applied Physics 41 ( 6A ) 3704-3709 2002

Research paper (scientific journal), Joint Work, Accepted

Adaptive pulse shaping of phase and amplitude of an amplified femtosecond pulse laser by direct reference to frequency-resolved optical gating traces

K. Ohno, T. Tanabe, and F. Kannari

Journal of Optical Society of America B 19 ( 11 ) 2781-2790 2002

Research paper (scientific journal), Joint Work, Accepted

Spatiotemporal measurements based on spatial spectral interferometry for ultrashort optical pulses shaped by a Fourier pulse shaper

T. Tanabe, H. Tanabe, Y. Teramura, and F. Kannari

Journal of Optical Society of America B 19 ( 11 ) 2795-2802 2002

Research paper (scientific journal), Joint Work, Accepted