Nippon Telegraph and Telephone Corporation

Hiromi Oohashi

Yasuo Shibata

Nobuhiro Kikuchi

Yuichi Thomori

Hiroyuki Ishii

Naoki Fujiwara

Yasuhiro Suzuki

Hiroshi Okamoto

Toshio Ito

Katsuaki Magari

Hiroyuki Kamioka

An object is to provide a wavelength tunable semiconductor laser device, a controller for the same and a control method for the same, which prevent wavelength drifts. The wavelength tunable semiconductor laser device includes an active region for oscillating a laser beam, and a wavelength tuning region for shifting a wavelength of the laser beam. In this device, a thermal compensation region for converting most of the inputted electric power to heat is provided adjacent to the wavelength tuning region, and the sum of an electric power inputted into the wavelength tuning region and an electric power inputted into the thermal compensation region is always kept constant.

Wavelength tunable semiconductor laser device, controller for the same, and control method for the same

An optical amplifier includes a first optical path, second optical path, semiconductor optical amplifier, and multi-mode interference 3-dB coupler. The first optical path guides oscillation light. The second optical path guides signal light. The semiconductor optical amplifier causes oscillation on the first optical path. The multi-mode interference 3-dB coupler crosses the first and optical paths in the gain medium of the semiconductor optical amplifier.

Optical amplifier

In an SOA characteristic evaluation method, the current is supplied to an SOA. An optical output generated by the SOA that have received the current is measured. Transmission light obtained by transmitting the optical output through a wavelength filter and/or a polarizer is measured. The characteristic of the SOA is evaluated on the basis of the measurement result of the optical output and the measurement result of the transmission light without using an optical input to the SOA. An SOA characteristic evaluation apparatus is also disclosed.

Semiconductor optical amplifier characteristic evaluation method and apparatus

Growing community of inventors

Kanagawa, Japan

Hiromi Oohashi