Fujitsu Corporation

Eudyna Devices Inc.

Fujitsu Quantum Devices Limited

Toshio Higashi

Hirokazu Tanaka

Yasuyuki Yamauchi

Emmanuel Le Taillandier De Gabory

Junji Watanabe

Takuya Fujii

Takashi Yamane

Manabu Komiyama

Shouichi Ogita

Tohru Watanabe

A laser device includes a cavity and a control portion. The cavity has an optical amplifier, a wavelength selectable portion having a changeable transmission wavelength range, and a mirror. The control portion controls the wavelength selectable portion so that the transmission wavelength range of the wavelength selectable portion is changed to a given range. The control portion controls the wavelength selectable portion so that the cavity outputs a desirable lasing wavelength light and optical intensity of the desirable lasing wavelength light is a given value, after controlling the wavelength selectable portion so that the cavity outputs the desirable lasing wavelength light.

Laser device, control device of laser device, method of controlling laser device, method of tuning wavelength of laser device and control data of laser device

A laser module has an optical amplifier, a first etalon and a wavelength selectable mirror. The first etalon has wavelength peaks at a given wavelength interval in transmission characteristics and transmits a light from the optical amplifier. The wavelength peaks are tunable. The wavelength selectable mirror acts as an external mirror of an external cavity laser including the optical amplifier, and has a relatively high reflection intensity at a part of wavelength range in an effective gain range of the optical amplifier. The effective gain range of the optical amplifier includes more than one wavelength peak of the first etalon. A reflection bandwidth where the wavelength selectable mirror has a relatively high reflection intensity is less than twice of the wavelength interval of the wavelength peaks of the first etalon.

Laser module and method of controlling wavelength of external cavity laser

A package for hermetically sealing a semiconductor laser which outputs light having a wavelength of 1.1 &#x3bc;m or more is filled with a gas containing an oxidizing gas such as oxygen or ozone. The oxidizing gas in the package oxidizes hydrogen in the package to prevent hydrogen embrittlement of electrodes that applies stress on electrodes and to suppress variation in the emission wavelength which would otherwise result from the application of stress.

Optical semiconductor device

The optical semiconductor device comprises a multiple quantum well structure of an AlGaInAs system material formed on an InP semiconductor substrate. The multiple quantum well structure comprises a barrier layer of a below 1.0 .mu.m of PL wavelength and a below 4.5 nm of film thickness active layer alternately laid one on another. An above 0.5% compressive strain is applied to the active layer. Thus the AlGaInAs/InP system optical semiconductor can have good temperature characteristics.

Optical semiconductor device including a multiple quantum well structure

An optical device comprises a light emitting device for emitting a light beam whose radiation angle is less than 15 degree and having a light emitting end surface on which a antireflection layer is formed, an optical fiber having a flat light incident end surface on which a antireflection layer is formed and a diffraction grating formed therein, and a substrate for supporting the light emitting device and the optical fiber so as to oppose the antireflection layer of the light emitting device to the antireflection layer of the optical fiber.

Optical device

An optical semiconductor device includes first and second cladding layers, a light guide layer sandwiched between the first and second cladding layers, and a layer structure provided in the light guide layer. The layer structure has a first periodic variation in a refractive index in a predetermined direction, and a second periodic variation in an optical gain in the predetermined direction. The first periodic variation has a period identical to that of the second periodic variation. The first periodic variation and the second periodic variation have a phase difference.

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Yamanashi, Japan

Toshio Higashi