| 摘要 |
PURPOSE:To reduce a return light rays reflected from an optical filter section so as to improve a S/N ratio by a method wherein a semiconductor optical waveguide type amplifier and a grating type optical filter are integrated and the grating is provided obliquely toward a direction in which an optical signal advances. CONSTITUTION:A planar optical waveguide 6 is provided in succession along a direction in which an optical signal advances from a core layer 4 of an optical amplifier 1, a grating face 5 is provided to the planar optical waveguide 6, and an optical filter section 2 is provided, where the grating face 5 is arranged so as to enable a grading angle to make an angle of one or more degrees with a direction perpendicular to a direction in which the optical signal advances. By these processes, an S/N ratio is made to decrease much in deterioration by restraining a noise component caused by a naturally released light and a gain saturation can be also restrained. And, as a device of this design can be manufactured through a monolithic processing method, a multi-stage integration is facilitated and the device can be made very small as compared with a device formed of unit components, so that the device is favorable for mounting. |
