Papers - Ota, Yasutomo

Method for generating a photonic NOON state with quantum dots in coupled nanocavities (vol 96, 013853, 2017)

Kenji Kamide, Yasutomo Ota, Satoshi Iwamoto, Yasuhiko Arakawa

PHYSICAL REVIEW A (AMER PHYSICAL SOC)  96 ( 2 )  2017.08

Research paper (scientific journal), Joint Work, Accepted,  ISSN  2469-9926

• Access to Document (DOI)

Enhanced optical Stark shifts in a single quantum dot embedded in an H1 photonic crystal nanocavity

H Takagi, Y Ota, N Kumagai, S Ishida, S Iwamoto, Y Arakawa

Applied Physics Express 10 (6), 062002 (IOP PUBLISHING LTD)  10 ( 6 )  2017

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1882-0778

　View Summary

We demonstrate large optical Stark shifts in a single quantum dot embedded in a modified H1 photonic crystal nanocavity. We designed the nanocavity to simultaneously possess a high Q factor, a small mode volume, and a high coupling efficiency to the external laser field. This nanocavity enabled the observation of a large Stark shift of 70 mu eV even under very weak laser irradiation. The large shift was sustained by only four intracavity photons on average, paving the way for the development of ultralow-power quantum/classical optical devices. (C) 2017 The Japan Society of Applied Physics

• Access to Document (DOI)

Demonstration of lasing oscillation in a plasmonic microring resonator containing quantum dots fabricated by transfer printing

A Tamada, Y Ota, K Kuruma, J Ho, K Watanabe, S Iwamoto, Y Arakawa

Japanese Journal of Applied Physics 56 (10), 102001 (Japan Society of Applied Physics)  56 ( 10 )  2017

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1347-4065

　View Summary

We demonstrate room-temperature lasing oscillation in a plasmonic microring resonator containing InAs/GaAs self-assembled quantum dots. The resonator is composed of a GaAs microring placed on an atomically flat silver surface. Such a structure was fabricated by transfer printing, through which we can pick the dielectric microring and place it on the silver surface at will, hence maintaining a high-quality metal surface without introducing any complex fabrication process. Our result will be important in the development of nanoscale light sources in future densely integrated plasmonic circuits.

• Access to Document (DOI)

Control of circularly polarized light electromagnetic field using chiral photonic crystals--Artificial optical activity and control of QD emission

S Iwamoto, S Takahashi, T Tajiri, Y Ota, Y Arakawa

IEICE Technical Report; IEICE Tech. Rep. 116 (389), 1-3  2017

Research paper (scientific journal), Joint Work, Accepted

Circularly polarized vacuum field in three-dimensional chiral photonic crystals probed by quantum dot emission

S Takahashi, Y Ota, T Tajiri, J Tatebayashi, S Iwamoto, Y Arakawa

Physical Review B 96 (19), 195404 (AMER PHYSICAL SOC)  96 ( 19 )  2017

Research paper (scientific journal), Joint Work, Accepted,  ISSN  2469-9950

　View Summary

The modification of a circularly polarized vacuum field in three-dimensional chiral photonic crystals was measured by spontaneous emission from quantum dots in the structures. Due to the circularly polarized eigenmodes along the helical axis in the GaAs-based mirror-asymmetric structures we studied, we observed highly circularly polarized emission from the quantum dots. Both spectroscopic and time-resolved measurements confirmed that the obtained circularly polarized light was influenced by a large difference in the photonic density of states between the orthogonal components of the circular polarization in the vacuum field.

• Access to Document (DOI)

A photonic crystal nanocavity with a quantum dot active region embedded by MBE regrowth

QH Vo, Y Ota, K Watanabe, T Kageyama, S Iwamoto, Y Arakawa

2017 22nd Microoptics Conference (MOC), 90-91 (Institute of Electrical and Electronics Engineers Inc.)  2017-   90 - 91 2017

Research paper (scientific journal), Joint Work, Accepted

　View Summary

We fabricated a two dimensional photonic crystal nanocavity embedding a spatially-isolated active region containing InAs quantum dots using crystal regrowth with molecular beam epitaxy. We observed a cavity mode with a quality factor over 10,000, despite the existence of a mound structure on top of the buried active region due to faceting during the regrowth.

• Access to Document (DOI)

Growth of InGaAs/GaAs nanowire-quantum dots on AlGaAs/GaAs distributed Bragg reflectors for laser applications

J Tatebayashi, S Kako, J Ho, Y Ota, S Iwamoto, Y Arakawa

Journal of Crystal Growth 468, 144-148  2017

Research paper (scientific journal), Joint Work, Accepted

Time-domain observation of vacuum rabi oscillations in a strongly coupled quantum dot-nanocavity system

K Kuruma, Y Ota, M Kakuda, S Iwamoto, Y Arakawa

CLEO: QELS_Fundamental Science, JTh1E. 4 (OSA - The Optical Society)  2017   1 - 2 2017

Research paper (scientific journal), Joint Work, Accepted,  ISSN  2160-9020

　View Summary

We report the time-domain observation of vacuum Rabi oscillations in a single quantum dot-photonic crystal nanocavity system under optical carrier injection. A significantlyimproved cavity Q-factor facilitates the direct access to the ultrafast exciton-photon dynamics.

• Access to Document (DOI)

Thresholdless quantum dot nanolaser

Y Ota, M Kakuda, K Watanabe, S Iwamoto, Y Arakawa

Optics express 25 (17), 19981-19994 (OPTICAL SOC AMER)  25 ( 17 ) 19981 - 19994 2017

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1094-4087

　View Summary

Thresholdless lasing is an outstanding challenge in laser science and is achievable only in devices having near unity quantum efficiency even when not lasing. Such lasers are expected to exhibit featureless linear light output curves. However, such thresholdless behavior hinders identification of the laser transition, triggering a long-lasting argument on how to identify the lasing. Here, we demonstrate thresholdless lasing in a semiconductor quantum dot nanolaser with a photonic crystal nanocavity. We employ cavity resonant excitation for enabling the thresholdless operation via focused carrier injection into high cavity field regions. Under conventional (above bandgap) excitation, the same nanolaser exhibits a typical thresholded lasing transition, thereby facilitating a systematic comparison between the thresholdless and thresholded laser transitions in the single device. Our approach enables a clear verification of the thresholdless lasing and reveals core elements for its realization using quantum dots, paving the way to the development of ultimately energyefficient nanolasers. (C) 2017 Optical Society of America

• Access to Document (DOI)

Thresholdless lasing with quantum dot gain

Y Ota, D Takamiya, K Watanabe, M Kakuda, S Iwamoto, Y Arakawa

CLEO: Science and Innovations, STh4N. 3 (OSA - The Optical Society)  2017   1 - 2 2017

Research paper (scientific journal), Joint Work, Accepted,  ISSN  2160-9020

　View Summary

We demonstrate thresholdless lasing with quantum dot gain, operated under cavity resonant excitation. The lasing behavior is systematically compared with that under conventional above bandgap excitation, providing a firm verification of the thresholdless operation.

• Access to Document (DOI)

Publisher's Note: Method for generating a photonic NOON state with quantum dots in coupled nanocavities [Phys. Rev. A 96, 013853 (2017)]

K Kamide, Y Ota, S Iwamoto, Y Arakawa

Physical Review A 96 (2), 029901  2017

Research paper (scientific journal), Joint Work, Accepted

Optical coupling between atomically thin black phosphorus and a two dimensional photonic crystal nanocavity

Y Ota, R Moriya, N Yabuki, M Arai, M Kakuda, S Iwamoto, T Machida, ...

Applied Physics Letters 110 (22), 223105 (AMER INST PHYSICS)  110 ( 22 )  2017

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0003-6951

　View Summary

Atomically thin black phosphorus (BP) is an emerging two dimensional (2D) material exhibiting bright photoluminescence in the near infrared region. Coupling its radiation to photonic nanostructures will be an important step toward the realization of 2D material based nanophotonic devices that operate efficiently in the near infrared region, which includes the technologically important optical telecommunication wavelength bands. In this letter, we demonstrate the optical coupling between atomically thin BP and a 2D photonic crystal nanocavity. We employed a home-build dry transfer apparatus for placing a thin BP flake on the surface of the nanocavity. Their optical coupling was analyzed through measuring cavity mode emission under optical carrier injection at room temperature. Published by AIP Publishing.

• Access to Document (DOI)

Method for generating a photonic NOON state with quantum dots in coupled nanocavities

K Kamide, Y Ota, S Iwamoto, Y Arakawa

Physical Review A 96 (1), 013853 (AMER PHYSICAL SOC)  96 ( 1 )  2017

Research paper (scientific journal), Joint Work, Accepted,  ISSN  2469-9926

　View Summary

We propose a method to generate path-entangled NOON-state photons from quantum dots and coupled nanocavities. In the systems we considered, cavity mode frequencies are tuned close to the biexciton two-photon resonance. Under appropriate conditions, the system can have the target NOON state in the energy eigenstate, as a consequence of destructive quantum interference. The NOON state can be generated by a resonant laser excitation. This method, first introduced for a two-photon NOON state (N = 2), can be extended toward a higher NOON state (N > 2) based on our recipe, which is applied to the case of N = 4 as an example.

• Access to Document (DOI)

Manipulation of dynamic nuclear spin polarization in single quantum dots by photonic environment engineering

CF Fong, Y Ota, S Iwamoto, Y Arakawa

Physical Review B 95 (24), 245423  2017

Research paper (scientific journal), Joint Work, Accepted

Guiding of laser light from a nanocavity in a three-dimensional photonic crystal

T Tajiri, S Takahashi, Y Ota, K Watanabe, S Iwamoto, Y Arakawa

2017 Conference on Lasers and Electro-Optics (CLEO), 1-2 (OSA - The Optical Society)  2017   1 - 2 2017

Research paper (scientific journal), Joint Work, Accepted,  ISSN  2160-9020

　View Summary

A nanocavity laser and two orthogonal waveguides are integrated in a threedimensional photonic crystal. Guiding of the laser light from the nanocavity through the waveguides is demonstrated experimentally.

• Access to Document (DOI)

プラズモニックマイクロリング共振器に埋め込まれた量子ドットにおける Purcell 効果の観測

A Tamada, Y Ota, K Kuruma, J Ho, K Watanabe, S Iwamoto, Y Arakawa

応用物理学会学術講演会講演予稿集 第 64 回応用物理学会春季学術講演会, 1029-1029  2017

Research paper (scientific journal), Joint Work, Accepted

単一自己形成量子ドットにおける光検出電子スピン共鳴の解析

A Ulhaq, MS Skolnick, Y Ota, S Iwamoto, Y Arakawa

 2017

Research paper (scientific journal), Joint Work, Accepted

励起スピン依存一方向レーザ発振が可能な光共振器の設計

W Lin, Y Ota, S Iwamoto, Y Arakawa

応用物理学会学術講演会講演予稿集 第 78 回応用物理学会秋季学術講演会, 845-845  2017

Research paper (scientific journal), Joint Work, Accepted

プラズモニック微小リング共振器中に埋め込まれた自己形成量子ドットからの単一光子発生

A Tamada, Y Ota, K Kuruma, J Ho, K Watanabe, S Iwamoto, Y Arakawa

応用物理学会学術講演会講演予稿集 第 78 回応用物理学会秋季学術講演会, 886-886  2017

Research paper (scientific journal), Joint Work, Accepted

Analysis on Optically-detected Electron Spin Resonance in Single Self-Assembled Quantum Dots

CF Fong, E Chekhovich, A Ulhaq, M Skolnick, Y Ota, S Iwamoto, ...

JSAP Annual Meetings Extended Abstracts The 64th JSAP Spring Meeting 2017 …  2017

Joint Work