A5069727073- Photonic and Optical Devices
- Semiconductor Lasers and Optical Devices
- Advanced Photonic Communication Systems
- Optical Network Technologies
- Semiconductor Quantum Structures and Devices
- Photonic Crystals and Applications
- Integrated Circuits and Semiconductor Failure Analysis
- Nanofabrication and Lithography Techniques
- Molecular Junctions and Nanostructures
- Optical Coatings and Gratings
- Semiconductor materials and interfaces
- Force Microscopy Techniques and Applications
- Neural Networks and Reservoir Computing
- Thin-Film Transistor Technologies
- Radio Frequency Integrated Circuit Design
- Photorefractive and Nonlinear Optics
- Advanced Fiber Optic Sensors
- Jewish and Middle Eastern Studies
- Acoustic Wave Resonator Technologies
- Advanced Data Compression Techniques
- Diamond and Carbon-based Materials Research
- Nanowire Synthesis and Applications
- Music and Audio Processing
- Physics of Superconductivity and Magnetism
- Middle East and Rwanda Conflicts
NTT (Japan)
2018-2025
Sony Computer Science Laboratories
2003
There has been an increasing need for small, low-cost, and low-power consumption optical transceivers short-reach fiber links. Waveguide-integrated photodetectors (PDs) with wide bandwidth high responsivity on Si photonics platforms are essential element these applications. We have fabricated O-band membrane PD which is suitable integration high-performance III-V-based devices such as lasers modulators, passive waveguide circuits the platforms. The consists of InGaAsP-bulk absorption core...
We demonstrate a heterogeneous integration of electrically-pumped membrane lasers and semiconductor optical amplifiers (SOAs) on thin-film lithium niobate (TFLN) platform by micro-transfer-printing (μTP) method. Thanks to the low coupling loss (∼1.0 dB) between InP-based photonic devices TFLN waveguides, mW-class output power laser low-power-consumption SOA are achieved. A 128-Gbit/s non-return-to-zero (NRZ) signal modulation is also demonstrated with Mach-Zehnder modulator an integrated...
We fabricate a membrane InGaAlAs electro-absorption modulator (EAM) integrated with distributed feedback (DFB) laser combining direct wafer bonding and epitaxial regrowth of InP-based layers on silicon-on-insulator wafer. Heterogeneous integration an multiple-quantum-well (MQW) layer into the Si photonics simplifies O-band EAMs diodes (LDs). LDs can be fabricated using same MQW because wide operating range bandgap MQWs. A compact high-speed lumped-electrode EAM made lateral p-i-n diode...
In this work, we fabricate directly modulated membrane distributed reflector (DR) lasers on a Si waveguide by utilizing micro-transfer printing method. Micro-transfer enables low-loss coupling between the and silicon photonics circuit, since it is back-end process, can test prior to integration. A laser as thick waveguides, which makes optical two quite easy. addition, with lateral <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p-i-n</i>...
A membrane laser with a buried sapphire layer on Si has 3-dB bandwidths of 40-25 GHz at 25-80°C. The demonstrates 80-Gbit/s PAM4 operations up to 80°C an energy cost 0.77 pJ/bit.
We demonstrate a wafer-level integration of distributed feedback laser diode (DFB LD) and high-efficiency Mach-Zehnder modulator (MZM) using InGaAsP phase shifters on Si waveguide circuits. The key to integrating materials with different bandgaps is combine direct wafer bonding multiple quantum well layer for the DFB LD regrowth bulk shifter. Buried an InP also employed define cores substrate. Both have 230-nm-thick lateral diodes, whose thickness less than critical III-V compound...
Ultrashort-distance optical interconnects are becoming increasingly important due to continuous improvements in servers and high-performance computers. As light sources such interconnects, directly modulated semiconductor lasers with an ultrasmall active region promising. In addition, using Si waveguides is provide low loss links functions as wavelength filtering switching. this paper, we demonstrate a wafer-scale heterogeneous integration of lambda-scale embedded active-region...
A low-cost and low-power-consumption optical transmitter with a narrow shoreline is crucial for short-reach communication. To increase the bandwidth density (Gbps/mm) at low cost, multiple components, including lasers, should be integrated on single chip. In this study, we develop sixteen-channel membrane laser array silica-based spot-size convertors SiO
Sixteen-channel DML array integrated with spot-size converters are fabricated on a SiO2/Si substrate footprint of 1.11 × 2.75 mm2, demonstrating 28- and 56-GBaud PAM4 operations BERs below the KP4-FEC limit after 2-km transmission.
Silicon photonics is a key technology for constructing large-scale photonic integrated circuits (PICs) because it enables wafer processes with high uniformity and quality.To further improve device characteristics, heterogeneous integration of III-V compound semiconductors that provide optical gain, modulation efficiency, non-linearity desired.This paper describes the membrane semiconductor devices have similar structure including thickness refractive index.These efficient coupling Si...
We fabricate a membrane InP-based electro-absorption modulator (EAM), in which an InGaAsP-based multiple-quantum-well (MQW) absorption region is buried with InP layer, on Si-waveguide circuits. By optical coupling between the MQW and Si core, low-loss large-absorption-length (300-μm-long) supermode waveguide designed to suppress electric-field screening at high input power. The EAM fabricated by combining direct bonding of layer regrowth thin template bonded silicon-on-insulator wafer. shows...
MPEG-4 parametric speech coding, harmonic vector excitation coding (HVXC) algorithm, is described. New features of the coder includes a quantizer scheme capable generating 2.0 and 4.0 kbps scalable bit-streams, where decoding possible using subset bit-stream. Time scale modification also without changing pitch nor phoneme for fast slow playback mode. Listening tests show that proposed method at provides significantly better quality than FS1016 CELP 4.8 kbps. In October 1998, HVXC was adopted...
We propose a new testing method to estimate the efficiency of Mach-Zehnder modulators by using only electrical characteristics, which is suitable for wafer-level testing. The breakdown voltage phase modulator shows clear relationship with efficiency.
We propose a new fiber alignment method using PN junction embedded grating coupler (GC). It enables us to quickly and easily search the optimum position for optical coupling between GC an fiber, enabling efficient on-wafer testing.
We describe a wafer prober integrated with an optical probe for wafer-level inspection of photonic circuits. The design the electric and circuit was optimized inspection. customized enabled us to perform high-volume high-speed over 400 elements, sufficiently reliable results were obtained. It took about 10 sec. evaluate propagation loss element. This technology will be key reducing costs devices.
We fabricate directly modulated membrane distributed-reflector lasers on a Si platform using micro-transfer printing method. Single-mode lasing with low threshold current of 1.2 mA and 50-Gbaud-class direct modulation are demonstrated.
We demonstrate distributed reflector lasers based on a III-V/Si membrane platform that includes quantum well intermixed Bragg reflectors offering tolerance to fabrication errors. The laser was used transmit 50-Gb/s PAM4 signals at 80°C.
We demonstrate an over-67-GHz-bandwidth O-band membrane photodetector (PD) with InGaAsP-bulk core on a Si photonics platform. The PD has fiber-to-PD responsivity of 0.6 A/W. Clear eye opening is achieved for 100-Gbit/s non-return-to-zero signal.
An InP-based membrane laser is transfer-printed onto a thin sapphire on Si substrate. Thanks to the low refractive index and high thermal conductivity of sapphire, fabricated has 3-dB bandwidth 26 GHz performs 53.125-Gbit/s operations at 50 degrees Celsius.
We demonstrate distributed reflector lasers based on a III-V/Si membrane platform. The threshold current is reduced by half of that detuned feedback laser owing to the use quantum-well intermixed Bragg reflectors; minimum 0.88 mA.
Membrane lasers on a SiC substrate offer high-speed direct modulation due to the high thermal dissipation and large optical confinement provided by SiC's high-thermal conductivity moderate refractive index (∼2.6). A remaining problem is coupling loss single-mode fiber (SMF) arising from difficulty in producing waveguide whose effective matches that of fiber. Here, overcome this, partially removed dip filled with SiO2, its surface planarized enable fabrication membrane spot-size converters...