A5007125650- Photonic and Optical Devices
- Optical Network Technologies
- Semiconductor Lasers and Optical Devices
- Advanced Photonic Communication Systems
- Semiconductor Quantum Structures and Devices
- Advanced Fiber Laser Technologies
- Advanced Optical Network Technologies
- Advanced Semiconductor Detectors and Materials
- Advanced Optical Sensing Technologies
- Photonic Crystals and Applications
- Quantum and electron transport phenomena
- Spectroscopy and Laser Applications
- Nanowire Synthesis and Applications
- Neural Networks and Reservoir Computing
- Software-Defined Networks and 5G
- Advancements in Semiconductor Devices and Circuit Design
- Radio Frequency Integrated Circuit Design
- GaN-based semiconductor devices and materials
- Plasmonic and Surface Plasmon Research
- Semiconductor materials and devices
- 3D IC and TSV technologies
- Laser Design and Applications
- Nanofabrication and Lithography Techniques
- Interconnection Networks and Systems
- Chalcogenide Semiconductor Thin Films
National Institute of Advanced Industrial Science and Technology
2012-2025
Photonics Electronics Technology Research Association
2012
Fujitsu (Japan)
1999-2008
Fujitsu (United States)
2005
New Energy and Industrial Technology Development Organization
2002
Ultrafast gain dynamics in quantum-dot (QD) optical amplifiers has been studied. It was found that there are at least three nonlinear processes, which attributed to carrier relaxation the ground states, phonon scattering, and capture from wetting layers into QDs. The relevant time constants were evaluated be /spl sim/90 fs, sim/260 sim/3 ps, respectively, under a 50-mA bias condition. dephasing sim/85 fs. third-order susceptibility (/spl chi//sup (3)/) by means of both transmission four-wave...
Conversion efficiency to longer wavelengths in four-wave-mixing-based wavelength conversion optical semiconductor amplifiers is generally much lower than that the opposite direction. This study demonstrates experimentally this feature drastically improved, and asymmetry between directions eliminated by using quantum dots active layer. We attribute a reduction linewidth enhancement factor due discreteness of electron states dots.
Wavelength conversion using nondegenerate four-wave mixing in quantum-dot optical amplifiers is investigated. From the detuning frequency dependence of χ(3), derived from efficiency, we consider that, within range experiment, spectral-hole burning and carrier heating are responsible, that their time constants, i.e., relaxation to ground state phonon scattering time, 60–140 200–400 fs, respectively. This indicates supply level via higher levels very fast a broad bandwidth comparable...
A nonlinear device capable of handling multiple wavelength channels simultaneously by using spectral-hole burning in the inhomogeneous broadening gain self-assembled quantum dots is proposed. The multichannel property this stems from localized absorption or change at pump within inhomogeneously broadened spectrum. spectral width modulation and its time evolution was also evaluated. result indicates applicability to operation.
Undoped GaSb crystals with mirror-like surfaces were obtained by liquid phase epitaxy from Sb-rich solutions. The background carrier concentration strongly depended on the growth temperature. By growing below 600 °C, we can obtain a crystal under 1016 cm−3. Photoluminescence studies showed that native defects related to Sb vacancies significantly reduced in crystal.
We developed ODU-XC, CDC-ROADM, and silicon photonics switch, built an eight-node network capable of 90Tbps based on NSI-CS standard protocol. Its energy consumption was orders magnitude lower than that achievable with IP routers.
n-channel body-tied partially depleted metal-oxide-semiconductor field-effect transistors (MOSFETs) were fabricated for large current applications on a silicon-on-insulator wafer with photonics-oriented specifications. The MOSFET can drive an electrical as 20 mA. We monolithically integrated this 2 × Mach-Zehnder interferometer optical switch having thermo-optic phase shifters. static and dynamic performances of the device are experimentally evaluated.
In this paper, we discuss nondegenerate four-wave mixing in a lasing long-cavity /spl lambda//4-shifted DFB laser using the beams as pump beams. A high conversion efficiency and wide range were experimentally demonstrated without assistance of Fabry-Perot resonance. Electric field profiles pump, signal, conjugate beam our are discussed. The third-order nonlinear susceptibilities InP-InGaAs MQW's then estimated from experimental results. We saturation characteristics ratio power to amplified...
An optical front end for a 10 Gbit/s receiver has been fabricated that features GHz Si preamplifier IC, flip-chip APD with an 80 gain-bandwidth product, and slant-end fibre coupling. Hybrid construction consisting of flipchip mounted directly on the chip minimises interconnect parasitics, coupling simplifies flat-package assembly fibre. sensitivity −23 dBm was achieved.
6.25GHz-spaced optical-comb-line selection either by low-coherence injection-locked laser (LC-ILLD) or with a combination ultra-narrow-filter and low-noise-fiber-amplifier (UNF-FA) is assessed. In 144Gbps DP-64QAM transmission the LC-ILLD outperforms UNF-FA approach for comb-OSNR-levels below 30dB.
We demonstrate low-loss and broadband light transition from III-V functional layers to a Si platform via two-stage adiabatic-crossing coupler waveguides. A 900-µm-long 2.7-µm-thick film waveguide consisting of GaInAsP core InP cladding is transferred onto an air-cladding photonic chip by the µ-transfer printing (µ-TP) method. An average optical coupling loss per joint 1.26 dB obtained in C + L telecommunication bands (1530-1635 nm). The correlation between alignment offset measured discussed...
Third-order optical nonlinear susceptibilities /spl chi//sup (3)/ in compressively strained and nonstrained InGaAs-InGaAsP quantum wells (QW's) under the population inversion condition are discussed. The small effective mass of QW's increases contribution carrier density pulsation effect heating (3)/. hole burning is also increased due to decrease carrier-carrier scattering rate. calculation including these effects shows an enhancement factor 3 0.8% compressive strain. values experimentally...
An Al0.053Ga0.947Sb avalanche photodiode (APD) has been fabricated and tested. First, measurement of an excess noise factor as well ionization rate ratio demonstrated. A low 3.8, which is 1.2 dB lower than the conventional GaInAs APD, obtained. From this factor, effective value hole-to-electron (keff) determined high 5, being in good agreement with (β/α) given by multiplication data. This keff highest ever reported for long-wavelength III-V APDs.
We report the growth of BeZnCdSe quantum-well laser diode (LD) structures with a short-period superlattice cladding layer and demonstrate continuous-wave lasing in pure-green spectral region (545 nm) at room temperature. The threshold current density voltage 5-µm-wide gain-guided were found to be 1.7 kA/cm2 10.4 V, respectively. This is sufficiently low compared that InGaN/GaN green LDs.
A polarisation-insensitive wavelength converter is proposed using bi-directional nondegenerate forward four-wave mixing in a lasing DFB-LD which the beams are used as pump waves. The suppresses polarisation sensitivity of conversion efficiency to within 0.4 dB, and demonstrates 10 Gbit/s optical phase conjugation.
The authors demonstrate frequency conversion by nondegenerate four-wave mixing in a lasing long-cavity λ/4-shifted DFB laser using the beam of as pump beam. Because long cavity and high power laser, wide range 3.7 THz is demonstrated without resonance.
We report on bistable operations in a microcavity formed an AlGaAs-based photonic crystal slab at telecommunication wavelengths. designed the cavity to achieve high quality ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$Q$</tex> )-factor, while maintaining small mode volume; this was accomplished by removal of single air hole. The fabricated exhibited resonant peak with -factor 1900 1548 nm. In nonlinear transmission measurement, when input...
Targeting future LAN applications, we demonstrate optical time domain multiplexing operation at 172-Gb/s using integratable semiconductor devices, i.e., intersubband transition all-optical gates, very short reach modules, amplifiers, and mode-locked laser diodes. Bit-error rate (<; 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-6</sup> ) well below the forward error correction limit was achieved successfully.
A wavelength converter that uses four-wave mixing (FWM) in an SOA-integrated distributed-feedback (DFB) laser was demonstrated. Lossless conversion up to 300-GHz detuning and a efficiency of -5 dB at 1-THz achieved. The device exhibited low ASE (noise) level, noise figure (NF) characteristics 24 for 16-nm observed. This high-efficiency FWM provided by single is promising optical shifters large-scale communication systems.
A surface-illuminated InP/GaInAs p-i-n photodiode with a planar, embedded structure has been fabricated. By minimizing the stray capacitance and by using semi-insulating substrates, reduced to 0.08 pF for diode diameter of 20 μm. It demonstrated that this very high-speed response greater than 10 GHz. The present is suitable not only as discrete but also optoelectronic integration.
We propose an operating principle for optical nonvolatile switch utilizing surface plasmon antenna resonance controlled by giant magnetoresistance. The spectra of array nanoscale dipole antennas composed Co/Cu multilayers with parallel and anti-parallel magnetization alignments were estimated a first-principle calculation finite difference time domain electromagnetic field analysis. extinction efficiency changed more than 40% in the infrared region due to alignment, demonstrating its promise...
We demonstrate dynamic optical path switching in 172-Gb/s OTDM transmissions of real ultra-high definition (UHD) video signals. To allow integration, the transmission system was composed semiconductor devices, which are newly developed CMOS-based transceivers, quantum-dot SOAs and monolithic all-optical gates based on inter-sub-band transitions a quantum well waveguide. In order to realize dynamically switchable (DS-OTDM), we novel clock distribution scheme using an null header (ONH). The...