| 摘要 |
PURPOSE:To obtain the function of detecting an output beam intensity with stabilized oscillation wavelength by arranging a beam receiver behind a reflective member arranged oppositely to a rear emission edge plane of a semiconductor laser element and receiving the laser beams emitted backward and reciprocate between the reflection mirror and the semiconductor laser edge plane by reflection at the back of the reflection mirror. CONSTITUTION:When a drive current is injected in a semiconductor laser element 1 to cause laser oscillation, laser beams are emitted forward and backward from an active layer 10 of the semiconductor laser element 1. The forward laser beams are used and the backward laser beams are reflected by a reflective plane 4 of a reflective member 3. After that, the reflected beams feed-backed to a rear edge plane 9 of the laser element are reflected again by this plane to be thrown to the reflective plane 4. The beams going a side from the reflective member 3 are projected to a beam receiver 8 as monitor beams and electric signals are detected, thereby enabling monitoring a laser output beam intensity of the semiconductor laser element 1. Also, those electric signal are feed-backed to a drive circuit of the semiconductor laser element 1 so as to control the drive current of the semiconductor laser element 1. Thus, the output beam of the semiconductor laser element 1 can be controlled at a constant intensity. |
