Takashi Kurokawa

Flip-chip bonded 0.85-µm Vertical-cavity Surface-emitting Laser Array using an AlGaAs substrate

Vertical-cavity surface emitting lasers (VCSELs) are promising for parallel optical interconnection and optical processing. 0.85-fim VCSELs offer some practical advantages over 0.98-(im ones [1-3] in that they can be used with standard optical fiber and more sensitive Si and GaAs-based receivers. However, it is generally difficult to fabricate 0.85-|im bottom-emitting VCSELs that have low parasitic capacitance and high thermal conductance by introducing flip-chip bonding. We previously reported 0.85-ja.m bottom-emitting VCSELs on an AlGaAs substrate [4-5]. However, their performance was not satisfactory and the utility of flip-chip bonding was not demonstrated.

Hybrid-integrated smart pixels for MCM and board-level optical interconnects

The input/output (I/O) bottleneck of CMOS VLSIs has recently become a severe problem due to increases in the operating frequency and the number of transistors. With the development of smart pixel technology, the use of optical interconnection has become a more attractive solution [l]-[3].

VCSEL-based smart pixels and their applications

Time division multiplexing has been generally used to increase the total throughput in optical communication systems. However, spatially-parallel optical interconnection technologies will be more effective over short distances (i.e., less than a few hundred meters). This is because data transmission in a parallel format makes system integration simple, reducing the latency of mux/demux functions, and thus results in lower power consumption and lower cost. VCSELs are very important for constructing parallel optical interconnection systems because they can emit a number of broadband optical signals simultaneously. In addition to their one- or two-dimensional structure, they have such advantages as a low cost, low operating current, and surface-normal emission. The surface-normal structure makes it easy to introduce optical input and output (I/O) into LSIs, which are important for constructing high-density optical interconnection systems.1

Logic-switchable Photonic Switch Arrays with 3-dB bandwidth of 300 MHz Monolithically Integrating MSMs, FETs, and MQW Modulators

Two-dimensional photonic array devices with fast switching and variable logic functions are very important in constructing optical processing circuits and photonic switching networks.

Low-contrast pre-coronagraph for extra contrast of dark-hole

We propose a low-contrast pre-coronagraph that can provide additional dark-hole contrast to a main coronagraph.

Direct image transmission through a multimode fiber using an optically addressed spatial light modulator

Direct image transmission through a multi-mode fiber is demonstrated using an optically addressed spatial light modulator as a phase conjugation mirror with an image-input function.