| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To solve the problem in the power supply of an optical disc, e.g. a DVD-RAM, that when the band of an APC circuit approaches or exceeds a signal frequency at the time of applying high speed APC required for writing, monitor noise due to return light is amplified entirely and APC is possibly disabled. <P>SOLUTION: The semiconductor laser comprises a semiconductor laser element 1 and a semiconductor submount substrate 2, and a transparent layer 4 of porous semiconductor is formed at a part of an inclining face 23 provided with a recess. A part of light 14 emitted from the semiconductor laser element 1 is reflected on a translucent film 25 and the remainder impinges partially on the submount substrate 2 before being received by light receiving elements (21, 22 and 24). Since the optical axis of return light 31 does not pass through the light receiving part of the light receiving elements (21, 22 and 24) after passing through a transparent layer 33, noise can be reduced greatly. <P>COPYRIGHT: (C)2003,JPO</p> |
