Hitachi, Ltd.

Akihiko Oka

Naoki Chinone

Shinji Sakano

Kazuhisa Uomi

Makoto Okai

Tomonobu Tsuchiya

Tsukuru Ohtoshi

Katutoshi Saito

A wavelength-tunable semiconductor laser device presenting a large wavelength-tunable range or a very-high-speed modulating semiconductor laser device having a distributed feedback structure including a diffraction grating as in the case of a DBR laser or a DFB laser incorporates therein a plurality of active layers differing from one another in constituent elements or composition ratio or thickness for reducing spectral line widths, while improving single-mode spectral oscillation characteristics.

Semiconductor laser device with plural active layers and changing

A wavelength tunable laser diode comprising a temperature variable heater separated from an active layer by a distance less than the thickness of a compound semiconductor substrate. Because the heater is located very close to the active layer, the response time of temperature change is improved. That in turn widens the tunable range of the laser diode.

Wavelength tunable laser diode

Semiconductor laser device capable of controlling wavelength shift

Growing community of inventors

Kokubunji, Japan

Akihiko Oka