| 摘要 |
PURPOSE:To detect deterioration in a semiconductor laser with high accuracy without being affected by a temperature difference, by deciding the deterioration in the semiconductor laser by relatively comparing the level of a light output detected in reproduction with the peak level of the light output detected in recording. CONSTITUTION:A semiconductor laser deterioration detector 100 is provided with a sample/hold circuit 9 which holds the level P1 of the light output detected in the reproduction, a peak detection circuit 10 which detects the peak level P2 of the light output detected in the recording, and a comparator 12 which compares the computed result P2/P1 of an arithmetic circuit 11 with a prescribed reference value V1. And the generation of the deterioration in the semiconductor laser 1 is decided by relatively comparing the level V1 of the light output detected in the reproduction with the peak level P2 of the light output detected in the recording. In such a way, the deterioration in the semiconductor laser 1 which emits a beam of light to perform optical reproduction and recording can be detected with the high accuracy without being affected by a temperature, etc. |
