Papers - Tanabe, Takasumi

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)

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)

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.

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)

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.

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)