Patent ID: 7508849
Filing Date: 2009-03-24
Classification: G02B,H01S

Abstract:
1. A wavelength tunable laser device, comprising: a semiconductor optical amplifier emitting a laser beam; a wavelength tunable filter arranged in an optical path of the laser beam; a first optical filter with a periodical transmission wavelength arranged in the optical path of the laser beam; two reflective members arranged so as to sandwich said semiconductor optical amplifier, said wavelength tunable filter, said first optical filter, therebetween, said two reflective members being resonating the laser beam; a phase shifter controlling a phase of the laser beam resonating between said two reflective members; a first unit to split light and a second unit to split light, each splitting a part of the laser beam passing through one of said two reflective members; a first optical detector detecting an intensity of the laser beam split by said first unit to split light; a second optical filter with a periodical transmission wavelength arranged in the optical path of the laser beam split by said second unit to split light, a rate of change in transmission peak wavelength of said first optical filter with a temperature change being greater than a rate of change in transmission peak wavelength of said second optical filter with the temperature change; and a second optical detector detecting an intensity of the laser beam passing through said second optical filter, wherein said first optical filter and said second optical filter are composed of different materials from each other.