| 摘要 |
PURPOSE:To stabilize beam output by feeding back a given quantity of laser beam in an extremely-limited period of time. CONSTITUTION:A feed-back means 2 made of beam condensing glass fiber 3 and a reflector 4 provided at the end surface of said glass fiber 3 for example is mounted at one output terminal of a semiconductor laser element 1. At this time, of the beam output of said element 1, the quantity of the feed-back beam effectively taken into the active layer of said element 1 is fixed larger than 3%. For reducing the unstability of laser beam unstability, the larger feed-back rates thereof than 3% are necessary. Further, the distance between the end surface of said element 1 and said reflector 4 is adjusted so that the time of beam reciprocation may be 10-60ps. If the distance l+L between said element 1 and reflector 4 is too small, the large first peak of reduced oscillation appears so that no feed-back effect is produced. If said distance is too large, on the other hand, large unstability takes place to output. |
