An electrically pumped light source on silicon is a key element needed for photonic integrated circuits on silicon. Here we report an electrically pumped AlGaInAs-silicon evanescent laser architecture where the laser cavity is defined solely by the silicon waveguide and needs no critical alignment to the III-V active material during fabrication via wafer bonding. This laser runs continuous-wave (c.w.) with a threshold of 65 mA, a maximum output power of 1.8 mW with a differential quantum efficiency of 12.7 % and a maximum operating temperature of 40 degrees C. This approach allows for 100's of lasers to be fabricated in one bonding step, making it suitable for high volume, low-cost, integration. By varying the silicon waveguide dimensions and the composition of the III-V layer, this architecture can be extended to fabricate other active devices on silicon such as optical amplifiers, modulators and photo-detectors.

Electrically pumped hybrid AlGaInAs-silicon evanescent laser

The fabrication and basic characteristics of a InGaAs/InGaAsP multi-quantum-well (MQW) electroabsorption modulator with a novel structure integrated with a distributed-feedback (DFB) laser are presented. A fundamental study was performed on the applicability of the InGaAs/InGaAsP MQW structure to an electroabsorption-type modulator. Efficient attenuation small hole pileup and small chirp characteristics of a discrete modulator based on this MQW structure were demonstrated experimentally. A study of the controllability of in-plane band-gap energy by the use of selective-area metal-organic chemical vapor deposition (MOCVD) was also demonstrated. The modulator was monolithically integrated with a MQW DFB laser of the same material. Using a low-capacitance semi-insulating buried heterostructure, over 14 GHz modulation under high-light-output operations up to +10 dBm was achieved. Modulation at 10 Gb/s with a modulation voltage swing of only 1 V/sub pp/ demonstrates the potential value of this system for 1.55- mu m lightwave communications. >

InGaAs/InGaAsP MQW electroabsorption modulator integrated with a DFB laser fabricated by band-gap energy control selective area MOCVD

Thanks to advanced semiconductor microfabrication technology, chip-scale integration and miniaturization of lab-on-a-chip components, silicon-based optical biosensors have made significant progress for the purpose of point-of-care diagnosis In this review, we provide an overview of the state-of-the-art in evanescent field biosensing technologies including interferometer, microcavity, photonic crystal, and Bragg grating waveguide-based sensors Their sensing mechanisms and sensor performances, as well as real biomarkers for label-free detection, are exhibited and compared We also review the development of chip-level integration for lab-on-a-chip photonic sensing platforms, which consist of the optical sensing device, flow delivery system, optical input and readout equipment At last, some advanced system-level complementary metal-oxide semiconductor (CMOS) chip packaging examples are presented, indicating the commercialization potential for the low cost, high yield, portable biosensing platform leveraging CMOS processes

Silicon Photonic Biosensors Using Label-Free Detection.

For high-bit-rate long-haul fiber optic communications, the avalanche photodiode (APD) is frequently the photodetector of choice owing to its internal gain, which provides a sensitivity margin relative to PIN photodiodes. APDs can achieve 5-10-dB better sensitivity than PINs, provided that the multiplication noise is low and the gain-bandwidth product is sufficiently high. In the past decade, the performance of APDs for optical fiber communication systems has improved as a result of improvements in materials and the development of advanced device structures. This paper presents a brief review of APD fundamentals and describes some of the significant advances

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Recent Advances in Telecommunications Avalanche Photodiodes

Error-free all-optical wavelength conversion at 168 Gb/s, which is the highest repetition rate ever reported, has been achieved by using a symmetric-Mach-Zehnder (SMZ)-type switch. Low-power-penalty 84-Gb/s operation is also demonstrated. The push-pull switching mechanism of the SMZ switch enables such ultrafast operation based on cross-phase modulation associated with the carrier depletion in a semiconductor optical amplifier. The configuration of the delayed-interference signal-wavelength converter, which is a simplified variant of the SMZ switch, is used in this experiment.

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168-Gb/s all-optical wavelength conversion with a symmetric-Mach-Zehnder-type switch

We have developed a hybrid-integrated symmetric Mach-Zehnder all-optical switch and evaluated the demultiplexing of 168-Gb/s data pulses at a repetition rate of 10 GHz with this switch. A compact, stable device was realized by assembling semiconductor optical amplifiers as nonlinear waveguides on a planar lightwave circuit in a self-aligned manner. A 6.0-ps switching window needed for 168-Gb/s demultiplexing was provided by the push-pull operation of the symmetric Mach-Zehnder all-optical switch. Demultiplexed signal light showed a high extinction ratio of better than 18 dB. Error-free demultiplexing with a bit error rate of 10/sup -11/ was achieved.

Demultiplexing of 168-Gb/s data pulses with a hybrid-integrated symmetric Mach-Zehnder all-optical switch

The bandgap energy of an In/InP multiquantum well structure, selectively grown by MOVPE, was controlled along the waveguide direction by controlling the mask stripe width. A butt-jointless DFB-LD/modulator light source was fabricated by using this technique.

DFB-LD/modulator integrated light source by bandgap energy controlled selective MOVPE

We have developed a novel three-dimensional high precision self-aligned assembly using stripe-type Au-Sn solder bumps and a micro-press solder bump formation method. This produces a high bonding precision of 1 /spl mu/m for optical device assembly in both lateral and vertical directions without the need for time-consuming optical axes alignment. Furthermore, we tested a hybrid integrated 4/spl times/4 optical matrix switch, in which multiple SSC-SOAG arrays were simultaneously positioned and optical fibers were passively positioned on a silica based PLC platform using this technology. Four optical chips and seven wiring chips are assembled on a planar lightwave circuit (PLC) platform. The insertion loss for each of these paths at an injection current of 40 mA was within a range of 9/spl plusmn/4 dB. The average extinction ratio was 40 dB. This self-aligned assembly technology was shown to be useful for building hybrid-integrated multichannel optical network components.

Multiple-chip precise self-aligned assembly for hybrid integrated optical modules using Au-Sn solder bumps

The present invention provides a compact, broad-band, and low-drive-voltage optical modulator module capable of generating any multilevel optical modulation. The optical modulator module according to an exemplary aspect of the present invention includes a digital segmented electrode structure optical modulator and m individual driving circuits. The digital segmented electrode structure optical modulator includes semiconductor optical waveguides and at least m waveguide-type optical phase modulator regions. An i-th individual driving circuit includes a driving circuit and a phase shift circuit. The driving circuit amplifies a digital input signal in synchronization with a clock signal and outputs the signal to an i-th waveguide-type optical phase modulator region. The phase shift circuit applies a delay to a signal branched from the clock signal. A j-th individual driving circuit receives an output signal from the phase shift circuit of a (j−1)-th individual driving circuit as a clock signal.

Optical modulator module and method for modulating optical signal

A semiconductor optical amplifier is mounted on a substrate which is provided for a package. Fiber blocks in which plural parallel internal optical fibers are supported are fitted to the package. The optical fibers are optically coupled with the semiconductor optical amplifier via optical waveguides formed on the substrate. V grooves for supporting the optical fibers which protrude out from the fiber block are formed on the substrate. Positionings of the optical fibers are performed by fitting the fiber blocks to the package so that end faces of the optical fibers butt against end walls of the V grooves.

Tomoaki Kato

Papers

Demultiplexing of 168-Gb/s data pulses with a hybrid-integrated symmetric Mach-Zehnder all-optical switch

DFB-LD/modulator integrated light source by bandgap energy controlled selective MOVPE

Multiple-chip precise self-aligned assembly for hybrid integrated optical modules using Au-Sn solder bumps

Optical modulator module and method for modulating optical signal

Optical module and a method for fabricating a same