Site: Mitsubishi Electric Corporation (MELCO)
Central Research Laboratory
1-1, Tsukaguchi Honmachi 8-Chome
Amagasaki, Hyogo 661, Japan
and
Optoelectronic & Microwave Devices Laboratory
4-1 Mizuhara Itami City, Hyogo 664, Japan

Date Visited: October 28, 1992

Report Author: V. Chan

ATTENDEES

NASA/NSF:

V. Chan
R. DePaula

HOSTS:

Dr. Masatami Iwamoto

Mr. Toshio Kashiwase

Dr. Koji Namura

Mr. Masaki Tabata

Dr. Shuichi Tai

Mr. Masaya Ito

Dr. Etsuji Omura

Dr. Saburo Takamiya

BACKGROUND

Both the MELCO Central Research Laboratory (M-CRL) and the Optoelectronic & Microwave Devices Laboratory are part of the research and development arm of MELCO. The R&D arm's responsibility is to strengthen the corporation's fundamental technologies, emphasizing new forms of energy, advanced electronic systems, new materials and components, industrial robots and other new technologies. Figure MELCO.1 outlines the MELCO R&D organization.

Figure MELCO.1. MELCO R&D Organization Chart

M-CRL is basic technology, biotechnology, laser and plasma physics, advanced electrotechnology, mechanical technology, system science and energy science and technology. The optoelectronic and microwave devices laboratory concentrates principally on semiconductor lasers, gaas ics and solar cells.

For related activities elsewhere in MELCO, see the site report by E. Miller on the visit to MELCO's Kamakura Works.

RESEARCH AND DEVELOPMENT ACTIVITIES

Space Robotics

Efforts are underway at M-CRL to establish the basic technologies for space robotics. One proposed application is the autonomous retrieval of a satellite in orbit. A motion simulator was developed to evaluate system performance under zero-g conditions. A visual recognition system was built using CCD image sensors and a digital processing algorithm.

Optical Disk Storage

A 90 mm optical disk drive including an embedded optical disk controller was developed. Advanced features such as high speed seek, and compatibility for optical-ROM and SCSI-2 host computer interface were implemented. The prototype shown appeared to be ready for production.

Large Space Antenna and Large Telescope

Large deployable antenna reflectors are highly desirable for earth observation and for satellite communications. For control of the shape of a flexible mesh antenna reflector, a recursive shape adjustment algorithm was shown to be quite effective by simulation and in trials on a mock-up model.

For large telescopes, mirror shape control to optical wavelength accuracies is a big challenge. The R&D activity uses a conventional deformable mirror (with actuators) to control the shape and a Shack-Hartmann wavefront analyzer to measure the wave front distortion. The mirror diameter is unusually large, 62 cm.

Telescope Pointing Control for Intersatellite Links

Feedback control algorithms are being explored to stabilize telescope pointing for ISLs. The effort includes both modeling of structural dynamics of the spacecraft and its payload, and the high speed feedback control algorithm.

The following activities are ongoing in the Optoelectronic Lab at Itami:

Lasers

Four types of lasers are being developed: an AlGaInP Visible Laser, 50 mW at 0.67 microns, an AlGaAs high power laser for optical disk and solid state laser pumping, InGaAsP lasers for long-haul transmission, analog transmission, fiber amplifier pumping, computer link and FDM systems, and InGaAs lasers at 980 nm, also for fiber amplifier pumping. These results are competitive with other Japanese and U.S. companies.

Detectors

InGaAs photodiode detectors are being developed for optical communication wavelengths of 1.2 to 1.6 microns.

SUMMARY

R&D at MELCO is very competitive with respect to other Japanese and U.S. companies. It is and will be a serious supplier of opto-electronic components.