The Furukawa Electric Co., Ltd.

Mizuki Oike

Takehiko Nomura

Hideyuki Nasu

Hiroshi Matsuura

Satoru Abe

Maiko Ariga

Kouki Sato

Hiroshi Takano

Toshikazu Mukaihara

Nobuyuki Shibata

Tomohiro Takagi

Toshimitsu Nishiwaki

Kengo Muranushi

Sayoko Ibe

Takuma Aoki

An optical modulehas a laser light source, optical branching meansfor receiving laser light from the laser light source, making a part of the laser light pass through the optical branching means and branching a remaining part of the laser light; a photodetecting portionP receiving the remaining part of the laser light branched from the optical branching meansand a packageholding therein the laser light source, the optical branching meansand the photodetecting portionP, the packagehaving stray light reducing meansandprovided therein to reduce stray light generated inside the package.

Optical module

An optical module includes a light-emitting device that outputs laser light, a temperature detection unit that is arranged in proximity to the light-emitting device and detects the temperature of the light-emitting device, a wavelength monitor unit that receives laser light outputted from the light-emitting device and having passed through an optical filter and monitors the wavelength of the laser light, and a temperature adjustment unit that adjusts the wavelength of laser light outputted from the light-emitting device based on a signal outputted from the wavelength monitor unit. The temperature adjustment unit adjusts the wavelength of the laser light so as to fall within a wavelength range, in which the wavelength is adjustable by the wavelength monitor unit, based on a signal from the temperature detection unit, and then adjusts the wavelength of the laser light so as to be locked at a predetermined wavelength based on the signal from the wavelength monitor unit. The signal from the temperature detection unit is used to correct lock wavelength shift caused by the temperature characteristic of the optical filter by estimating the temperature of the optical filter based on the temperature of the light-emitting device.

Method of controlling a wavelength of a semiconductor laser, optical module, optical transmitter, WDM optical transmission apparatus, and method of controlling a wavelength of an optical module

A wavelength controller includes a wavelength locker module, having a prism for dividing incident light into first and second branched light beams, a first light quantity detector for receiving the first branched light beam through a wavelength selective filter and a second light quantity detector for directly receiving the second branched light beam, and detects and suppresses a wavelength variation in incident light entering the module based on outputs of the light quantity detectors.

Wavelength locker module and wavelength controller for optical communication

An optical attenuator ( ) has a substrate (glass substrate) ( ) and an optical attenuation film ( ) that attenuates an input light with a predetermined optical attenuation factor, and the optical attenuation film ( ) is disposed on a light input face ( ) of the substrate ( ). An angle defined by the light input face ( ) and the light output face ( ) of the substrate ( ) is set to 0.15&deg; to 0.5&deg;. A protective film ( ) for preventing the deterioration of the optical attenuation film ( ) is formed on a surface of the optical attenuation film ( ).

Optical attenuator and optical attenuator module

A wavelength monitor capable of obtaining an optical detection signal of high quality is proposed. In the wavelength monitor, a light incident surface of an optical filter is disposed with an inclination relative to the light incident direction. With this arrangement, it is possible to make the route of a reflection light that has been reflected from the light incident surface of the optical filter deviate large from the route of an incident light that has been incident to the optical filter. Consequently, the reflected light is prevented from being incident to a semiconductor laser device or optical detectors.

Wavelength monitor and laser module

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Tokyo, Japan

Mizuki Oike