| 摘要 |
PROBLEM TO BE SOLVED: To solve such a problem that, when a high speed APC necessary for writing is applied in an optical disk light source such as DVD-RAM or the like, monitor noise due to returning light is entirely amplified as noise if a band of an APC circuit becomes equivalent to or more than a signal, and as a result, the APC often becomes impossible. SOLUTION: This semiconductor laser is provided with a groove 4 having a specified thickness between a semi-transmitting mirror 25 and a light receiving element 2 arranged behind the mirror 25, or within the light receiving element 2. Due to such a structure, the light axis of the returning light becomes impossible to be arranged so that it does not pass through the light receiving part 7 of the light receiving element after passing the groove, and a high-speed FAPC method can be used to control the returning light so that all or almost part thereof does not enter the light receiving part and returning light noise can be greatly reduced. |
