Nippon Telegraph and Telephone Corporation

Mitsuru Naganuma

Yasuhiro Suzuki

Masashi Nakao

Masahiro Yuda

Osamu Mitomi

Masahiro Ikeda

Hiroshi Yasaka

Kiyoyuki Yokoyama

Junichi Nakano

Kazuo Kasaya

Masanobu Okayasu

Osamu Mikami

Katsuhiko Kurumada

Shingo Uehara

Yasuhiro Kondou

An optical functional device includes a semiconductor substrate, an optical functional layer provided on said semiconductor substrate and selected from the group consisting of a light emitting layer, a light absorbing layer, and an optical waveguide layer. The optical functional layer has a multi-quantum well layer. Preferably, the semiconductor substrate is a nonplanar semiconductor substrate having a ridge and two grooves adjacent said ridge, said ridge having a ridge width of from 1 to 10 .mu.m, a ridge height of from 1 .mu.m to 5 .mu.m, and a gap distance of from 1 .mu.m to 10 .mu.m. Such an optical functional device can be fabricated by growing, on a nonplanar semiconductor substrate having a specified dimension of the ridge, a strained multi-quantum well layer by metalorganic vapor phase epitaxy. Integrated optical device or circuit preferably includes an optical functional device on the nonplanar semiconductor substrate of a specified range of ridge shape factors. An integrated optical device can be fabricated by combination of a plurality of optical functional devices having slightly different compositions and including a part of a strained multi-quantum well layer monolithically grown on a nonplanar semiconductor substrate.

Method for producing various semiconductor optical devices of differing

A wide band distributed Bragg reflector having a reflectivity extremely greater than that of a narrow band distributed Bragg reflector mirror portion on the output side of a bistable type wavelength conversion device is arranged on the incident side. The input light in TM polarization mode is used as an input signal light and the wavelength conversion is performed by tuning the narrow band distributed Bragg reflection mirror portion on the output side from which an output light in TE polarization mode outgoes perpendicularly to the input light. The input signal light and the output signal light are polarized in such a manner that they are perpendicular to one another and, therefore, the device can be realized as a one-directional device. The use of any isolator is not required.

Semiconductor wavelength conversion device

Growing community of inventors

Kunitachi, Japan

Mitsuru Naganuma