A5087731621- Photonic and Optical Devices
- Optical Network Technologies
- Advanced Photonic Communication Systems
- Semiconductor Lasers and Optical Devices
- Advanced Fiber Laser Technologies
- Neural Networks and Reservoir Computing
- Advanced Fiber Optic Sensors
- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Advanced Optical Network Technologies
- Quantum many-body systems
- Photorefractive and Nonlinear Optics
- Quantum optics and atomic interactions
- Neural dynamics and brain function
- Photonic Crystals and Applications
- Neural Networks and Applications
- Advanced Memory and Neural Computing
- Mechanical and Optical Resonators
- Nonlinear Dynamics and Pattern Formation
- Advanced Frequency and Time Standards
- Semiconductor Quantum Structures and Devices
- Advanced Optical Sensing Technologies
- IoT and Edge/Fog Computing
- Optical measurement and interference techniques
- Slime Mold and Myxomycetes Research
NTT (Japan)
2015-2025
NTT Basic Research Laboratories
2005-2020
Showa Denko (Japan)
2000
JEOL (Japan)
2000
Benchmarking the coherent Ising machine and D-Wave quantum annealer sheds light on importance of connectivity.
Computers based on physical systems are increasingly anticipated to overcome the impending limitations digital computer performance. One such is a coherent Ising machine (CIM) for solving combinatorial optimization problems. Here, we report CIM with 100,512 degenerate optical parametric oscillator pulses working as spins. We show that delivers fine solutions maximum cut problems of 100,000-node graphs drastically faster than standard simulated annealing. Moreover, CIM, when operated near...
Terahertz (THz)-bandwidth continuous-wave (CW) squeezed light is essential for integrating quantum processors with time-domain multiplexing (TDM) by using optical delay line interferometers. Here, we utilize a single-pass parametric amplifier (OPA) based on single-spatial-mode periodically poled ZnO:LiNbO3 waveguide, which directly bonded onto LiTaO3 substrate. The OPA allows THz bandwidth, and the absence of higher-order spatial modes in structure helps avoid degradation squeezing. In...
This article proposes an optical parametric amplifier (OPA), as inline-repeater, using a periodically-poled-LiNbO 3 (PPLN) waveguide with over-10-THz amplification bandwidth, and also presents wide-band wavelength-division-multiplexing (WDM) inline-amplified transmission the OPA.Our PPLN-based OPA is polarization-independent has spectrally efficient configuration by filtering phase-conjugated signals (idlers).We implemented our half its ideal bandwidth because of limited number PPLN...
Abstract Nonlinear dynamics of spiking neural networks have recently attracted much interest as an approach to understand possible information processing in the brain and apply it artificial intelligence. Since can be processed by collective neurons, fine control is desirable for neuromorphic devices. Here we show that photonic neurons implemented with paired nonlinear optical oscillators controlled generate two modes bio-realistic changing optical-pump amplitude. When are coupled a network,...
The optical parametric amplifier (OPA) has attractive features for communications, such as a wideband, high gain, and fast transient response. In addition, by using idler light, which is phase-conjugated light generated in the amplification process, various kinds of signal processing, fiber-nonlinearity mitigation, wavelength conversion, phase-sensitive amplification, can be performed. A periodically poled LiNbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Many problems in mathematics, statistical mechanics, and computer science are computationally hard but can often be mapped onto a ground-state-search problem of the Ising model approximately solved by artificial spin-networks coupled degenerate optical parametric oscillators (DOPOs) coherent machines. To better understand their working principle optimize performance, we analyze dynamics during ground state search 2D models with up to 1936 mutually DOPOs. For regular as well frustrated...
Phase-sensitive detection is the essential projective measurement for measurement-based continuous-variable quantum information processing. The bandwidth of conventional electrical phase-sensitive detectors up to several gigahertz, which would limit speed computation. It theoretically proposed realize terahertz-order by using all-optical with an optical parametric amplifier (OPA). However, there have been experimental obstacles achieve large gain continuous waves, required use in Here, we...
Combinatorial optimizers using physical systems, or “Ising machines,” have been intensively studied as a way of computation that is more efficient than current digital computers. Here, we demonstrate coherent Ising machine (CIM) based on degenerate optical parametric oscillator (DOPO) pulses can find solutions to large-scale maximum independent set problems, which an essential optimization problem closely related real-world tasks. We implemented stable external field for each spin...
Phase-sensitive amplifiers (PSAs) via the optical parametric amplification (OPA) process are capable of near-noiseless amplification, which can improve performance communications systems. OPA based on periodically poled lithium niobate (PPLN) waveguides is a proven means to implement PSA with low additional nonlinear effects, such as frequency chirp, stimulated Brillouin scattering, and crosstalk due unwanted interactions among pump other signal waves. However, fiber compatibility challenge...
We demonstrate a compact and variable-optical-attenuator (VOA) integrated coherent receiver with silica-based planar lightwave circuit (PLC). To realize the receiver, we integrate VOA in single PLC chip polarization beam splitters optical 90-degree hybrids, employ stable optoelectronic coupling system consisting of micro lens arrays photodiode (PD) subcarriers high-speed right-angled signal lines. 27x40x6 mm package, successfully demodulate 128-Gbit/s division multiplexed (PDM) quadrature...
We report a coherent Ising machine (CIM) that can simulate the model with external magnetic fields. To represent spins, CIM employs degenerate optical parametric oscillator (DOPO) pulses, which are coupled by measurement-feedback scheme. By adding to feedback signal term is proportional given field and an absolute value of measured amplitude DOPO pulse, networked pulses behave like spins in field. Using CIM, we implement antiferromagnetically one- two-dimensional networks uniform At...
Here researchers investigate how well a coherent Ising machine (CIM), based on network of degenerate optical parametric oscillators, simulates the thermodynamic properties two-dimensional square-lattice model. Assuming that CIM samples can be regarded as canonical ensemble, authors estimate effective temperature spins (optical pulses) using maximum-likelihood estimation. Using temperature, quantities obtained from exhibit phase-transition-like behavior matches analytical and numerical...
We propose a novel structure that reduces the switching power of silica-based thermooptic switch (TOSW). The consists silicon trenches and heat insulating grooves, which are formed beneath beside arms Mach-Zehnder interferometer, respectively. optimize using differential-element method (DEM) fabricate 2 /spl times/ TOSW with only 90 mW, namely, 75% less than conventional TOSW. also obtain an insertion loss about 1 dB extinction ratio over 30 response time from 0% to 90% 4.9 ms. then use 8...
To extend the operation wavelength range of dual-polarization optical hybrids (DPOH), we propose a highly symmetrical interferometer design for polarization beam splitter and an hybrid to reduce temperature dependence. The successfully decreases this dependence, fabricated DPOH with silica-based planar lightwave circuits provides temperature-insensitive performance extinction ratio over 25 dB phase errors less than 3 degrees entire C- L-bands.
Abstract The phenomenon of partial synchronization has attracted significant interest in the field nonlinear dynamics, largely due to observations related phenomena real-world situations. In particular, coexistence synchronized and desynchronized phases, known as a chimera state, been subject intense study. this work, we experimentally demonstrate that networks identical photonic spiking neurons based on coupled degenerate optical parametric oscillators can exhibit various states which,...
We propose a silica-based 2/spl times/2 thermooptic switch using heat insulating grooves and trenches on Si substrate to reduce electric power consumption. The switching of fabricated was successfully reduced 135 mW, less than 1/3 that conventional switch. No detrimental effect optical characteristics observed: we obtained the insertion loss 1 dB, extinction ratio better 30 dB no polarization dependency.
To realize a DP-QPSK receiver PLC, we heterogeneously integrated eight high-speed PDs on silica-based PLC platform with PBS, 90-degree optical hybrids and VOA. The use of 2.5%-Δ waveguide reduced the size to 11 mm x mm. We successfully demonstrated 32 Gbaud signal demodulation PLC.
Abstract The Potts model describes Ising-model-like interacting spin systems with multivalued components, and ground-state search problems of the can be efficiently mapped onto various integer optimization thanks to rich expression spins. Here, we demonstrate a solver this based on hybrid computation using physical digital architectures, wherein computer updates interaction matrices in iterative calculations Ising-model solvers. This update interactions corresponds learning from Ising...
We demonstrated an extremely low power consumption thermooptic switch using suspended ridge and silicon-silica hybrid waveguide structures. The switching was successfully reduced to only 0.6 mW.
We report the design and fabrication of a hybrid-integration-type coherent receiver. optimize receiver building blocks, achieve -25-dB common-mode rejection ratio 20-dB signal input power dynamic range.
A novel integrated polarisation beam splitter on a silica-based planar lightwave circuit that utilises the waveguide birefringence dependence core width is proposed. It was successfully confirmed fabricated has extinction ratio of > 21 dB over wide wavelength range 1530 to 1620 nm.
The extension of optical add/drop multiplexing (OADM) systems to metro-core and metro-access networks has led the need for economical compact OADM devices. In this paper, we demonstrate a 1-in. <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> 100 GHz spacing 40-channel (ch) single-chip variable attenuator multiplexer/demultiplexer based on monolithic 2.5%-Delta silica planar lightwave circuit (PLC) stacked photodiode arrays. We also...
We developed in-line PSA for the simultaneous amplification of wavelength-multiplexed and polarization-multiplexed QAM signals. achieved >20-dB gain a 12-nm bandwidth 16-channel PDM-16QAM signals with an inherent characteristic 5.1-dB SNR advantage.