Papers - Ota, Yasutomo

GaAs valley photonic crystal waveguide with light-emitting InAs quantum dots

T Yamaguchi, Y Ota, R Katsumi, K Watanabe, S Ishida, A Osada, ...

Applied Physics Express 12 (6), 062005 (IOP Publishing)  12 ( 6 ) 062005 - 062005 2019

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

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We report a valley photonic crystal (VPhC) waveguide in a GaAs slab with InAs
quantum dots (QDs) as an internal light source exploited for experimental
characterization of the waveguide. A topological interface state formed at the
interface between two topologically-distinct VPhCs is used as the waveguide
mode. We demonstrate robust propagation for near-infrared light emitted from
the QDs even under the presence of sharp bends as a consequence of the
topological protection of the guided mode. Our work will be of importance for
developing robust photonic integrated circuits with small footprints, as well
as for exploring active semiconductor topological photonics.


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Three-dimensional photonic crystal simultaneously integrating a nanocavity laser and waveguides

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

Optica 6 (3), 296-299 6 ( 3 ) 296 - 299 2019

Research paper (scientific journal), Joint Work, Accepted

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Strongly coupled single-quantum-dot–cavity system integrated on a CMOS-processed silicon photonic chip

A Osada, Y Ota, R Katsumi, M Kakuda, S Iwamoto, Y Arakawa

Physical Review Applied 11 (2), 024071 (American Physical Society (APS))  11 ( 2 )  2019

Research paper (scientific journal), Joint Work, Accepted

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Quantum photonic integrated circuit (QPIC) is a promising tool for
constructing integrated devices for quantum technology applications. In the
optical regime, silicon photonics empowered by
complementary-metal-oxide-semiconductor (CMOS) technology provides optical
components useful for realizing large-scale QPICs. Optical nonlinearity at the
single-photon level is required for QPIC to facilitate photon-photon
interaction. However, to date, realization of optical elements with
deterministic( i.e., not probabilistic) single-photon nonlinearity by using
silicon-based components is challenging, despite the enhancement of the
functionality of QPICs based on silicon photonics. In this study, we realize
for the first time a strongly coupled InAs/GaAs quantum dot-cavity quantum
electrodynamics (QED) system on a CMOS-processed silicon photonic chip. The
heterogeneous integration of the GaAs cavity on the silicon chip is performed
by transfer printing. The cavity QED system on the CMOS photonic chip realized
in this work is a promising candidate for on-chip single-photon nonlinear
element, which constitutes the fundamental component for future applications
based on QPIC, such as, coherent manipulation and nondestructive measurement of
qubit states via a cavity, and efficient single-photon filter and router.


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Spin-dependent directional emission from a quantum dot ensemble embedded in an asymmetric waveguide

W Lin, Y Ota, S Iwamoto, Y Arakawa

Optics letters 44 (15), 3749-3752 (The Optical Society)  44 ( 15 ) 3749 - 3749 2019

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0146-9592

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In this study, we examine a photonic wire waveguide embedded with an ensemble
of quantum dots that directionally emits into the waveguide depending on the
spin state of the ensemble. This is accomplished through the aid of the
spin-orbit interaction of light. The waveguide has a two-step stair-like cross
section and embeds quantum dots (QDs) only in the upper step, such that the
circular polarization of emission from the spin-polarized QDs controls the
direction of the radiation. We numerically verify that more than 70% of the
radiation from the ensemble emitter is toward a specific direction in the
waveguide. We also examine a microdisk resonator with a stair-like edge, that
supports selective coupling of the QD ensemble radiation into a whispering
galley mode rotating unidirectionally. Our study provides a foundation for
spin-dependent optoelectronic devices.


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Single plasmon generation in an InAs/GaAs quantum dot in a transfer-printed plasmonic microring resonator

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

ACS Photonics 6 (5), 1106-1110 6 ( 5 ) 1106 - 1110 2019

Research paper (scientific journal), Joint Work, Accepted,  ISSN  2330-4022

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Quantum-dot single-photon source on a CMOS-processed silicon waveguide

R Katsumi, Y Ota, A Osada, T Yamaguchi, T Tajiri, M Kakuda, S Iwamoto, ...

CLEO: QELS_Fundamental Science, FM1M. 2 (IEEE)  FM1M ( 2 ) 1 - 2 2019

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

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We report a quantum-dot single-photon source integrated onto a CMOS-processed silicon waveguide. The necessary hybrid integration was done in a simple pick-and-place manner with transfer printing, thus fully maintaining the compatibility with CMOS-back-end technology. (C) 2019 The Author(s)

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Quantum-dot single-photon source on a CMOS silicon photonic chip integrated using transfer printing

R Katsumi, Y Ota, A Osada, T Yamaguchi, T Tajiri, M Kakuda, S Iwamoto, ...

APL Photonics 4 (3), 036105 4 ( 3 )  2019

Research paper (scientific journal), Joint Work, Accepted,  ISSN  2378-0967

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Photonic crystal nanocavity based on a topological corner state

Y Ota, F Liu, R Katsumi, K Watanabe, K Wakabayashi, Y Arakawa, ...

Optica 6 (6), 786-789 6 ( 6 ) 786 - 789 2019

Research paper (scientific journal), Joint Work, Accepted,  ISSN  2334-2536

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© 2019 Optical Society of America. Topological photonics has emerged as a novel approach to engineering the flow of light and provides unprecedented means for developing diverse photonic elements, including robust optical waveguides immune to structural imperfections. However, the development of nanoscale standing-wave cavities in topological photonics is rather slow, despite its importance when building densely integrated photonic integrated circuits. In this Letter, we report a photonic crystal nanocavity based on a topological corner state, supported at a 90-deg-angled rim of a twodimensional photonic crystal. A combination of the bulk-edge and edge-corner correspondences guarantees the presence of the higher-order topological state in a hierarchical manner. We experimentally observe a corner mode that is tightly localized in space while supporting a high Q factor over 2,000, verifying its promise as a nanocavity. These results cast new light on the way to introduce nanocavities in topological photonics platforms.

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Photoluminescence properties as a function of growth mechanism for GaSb/GaAs quantum dots grown on Ge substrates

Zon, S Thainoi, S Kiravittaya, A Tandaechanurat, S Kanjanachuchai, ...

Journal of Applied Physics 126 (8), 084301 (AIP Publishing)  126 ( 8 ) 084301 - 084301 2019

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0021-8979

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Nanocavity based on a topological corner state in a two-dimensional photonic crystal

Y Ota, R Katsumi, K Watanabe, F Liu, K Wakabayashi, S Iwamoto, ...

CLEO: Science and Innovations, SW4J. 1 (Optics InfoBase Conference Papers)  Part F129-CLEO\_SI 2019 2019

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

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© 2019 The Author(s) 2019 OSA. We demonstrate a photonic crystal nanocavity based on a topological corner state. The design exploits the hierarchical bulk-edge-corner correspondence for the two-dimensional photonic crystal, opening a deterministic route to introduce nanocavities in topological photonics platforms.

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Local tuning of transfer-printed quantum-dot single-photon sources on a CMOS silicon chip

R Katsumi, Y Ota, A Osada, T Tajiri, T Yamaguchi, M Kakuda, S Iwamoto, ...

2019 24th Microoptics Conference (MOC), 308-309 (IEEE)     308 - 309 2019

Research paper (scientific journal), Joint Work, Accepted

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We report local wavelength tuning of quantum-dot single-photon sources integrated on a CMOS silicon chip as well as in-situ spectral matching between two dissimilar sources. All the necessary heterogeneous integration processes were performed in a simple pick-and-place manner based on transfer printing, largely facilitating the fabrication of complicated device structures.

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An on-chip full poincaré beam emitter based on an optical micro-ring cavity

W Lin, Y Ota, Y Arakawa, S Iwamoto

CLEO: Science and Innovations, SW4J. 4 (Optics InfoBase Conference Papers)  Part F129-CLEO\_SI 2019 2019

Research paper (scientific journal), Joint Work, Accepted

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We numerically demonstrate an on-chip full Poincaré beam emitter. We employ a micro-ring resonator augmented with scatterer arrays, which synthesizes the Poincaré beam as a superposition of twisted beams carrying different orbital- and spin-angular momenta.

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An On-chip Full Poincare Beam Emitter Based on an Optical Micro-ring Cavity

Lin Wenbo, Ota Yasutomo, Arakawa Yasuhiko, Iwamoto Satoshi

2019 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)  2019

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

In-situ wavelength tuning of quantum-dot single-photon sources integrated on a CMOS silicon chip

R Katsumi, Y Ota, A Osada, T Tajiri, T Yamaguchi, M Kakuda, S Iwamoto, ...

arXiv preprint arXiv:1909.13452  2019

Research paper (scientific journal), Joint Work, Accepted

Hybrid integration of quantum dot-nanocavity systems on silicon

Y Ota, R Katsumi, A Osada, M Kakuda, S Iwamoto, Y Arakawa

Frontiers in Optics, FM3D. 4 (Optics InfoBase Conference Papers)  Part F144-FiO 2019 2019

Research paper (scientific journal), Joint Work, Accepted

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We discuss a transfer printing method for on-silicon hybrid integration. This technique simplifies the integration process of III-V quantum dots in nanocavities on CMOS-processed circuits, enabling single photon sources and cavity QED systems on Si.

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Growth‐Rate‐Dependent Properties of GaSb/GaAs Quantum Dots on (001) Ge Substrate by Molecular Beam Epitaxy

P Phienlumlert, S Thainoi, S Kiravittaya, A Tandaechanurat, N Nuntawong, ...

physica status solidi (a) 216 (1), 1800499  2019

Research paper (scientific journal), Joint Work, Accepted

Nanowire-quantum-dot lasers on flexible membranes

Jun Tatebayashi, Yasutomo Ota, Satomi Ishida, Masao Nishioka, Satoshi Iwamoto, Yasuhiko Arakawa

Applied Physics Express (Japan Society of Applied Physics)  11 ( 6 )  2018.06

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1882-0786

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We demonstrate lasing in a single nanowire with quantum dots as an active medium embedded on poly(dimethylsiloxane) membranes towards application in nanowire-based flexible nanophotonic devices. Nanowire laser structures with 50 quantum dots are grown on patterned GaAs(111)B substrates and then transferred from the as-grown substrates on poly(dimethylsiloxane) transparent flexible organosilicon membranes, by means of spin-casting and curing processes. We observe lasing oscillation in the transferred single nanowire cavity with quantum dots at 1.425 eV with a threshold pump pulse fluence of ∼876 μJ/cm2, which enables the realization of high-performance multifunctional NW-based flexible photonic devices.

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world's highest Q-Factor: Fabrication of a large-area 3D photonic crystal for 3D photonic circuits

Takahashi Shun, Tajiri Takeyoshi, Watanabe Katsuyuki, Ota Yasutomo, Iwamoto Satoshi, Arakawa Yasuhiko

ELECTRONICS LETTERS 54 ( 5 ) 257 - 257 2018.03

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0013-5194

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Circularly polarized light emission by semiconductor-based three-dimensional chiral photonic crystals

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

IEICE Technical Report; IEICE Tech. Rep. 118 (349), 7-10  2018

Research paper (scientific journal), Joint Work, Accepted

Advanced Photonic Crystal Nanocavity Quantum Dot Lasers

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

IEICE Transactions on Electronics 101 (7), 553-560 E101C ( 7 ) 553 - 560 2018

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1745-1353

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