| 摘要 |
PURPOSE:To reduce a return beam noise and simultaneously to reduce the dispersion of the return beam noise, as well regardless of the dispersion of an LD. CONSTITUTION:This device is constituted so that the LD 2 is driven by superposing high frequency AC by a variable power source 13 for an HFM to DC driving current supplied to the LD 2 by an LD driving power source 12, and on the other hand, the output voltage value of the variable power source 13 for the HFM is varied and the effective condition of the HFM, that is, the change DELTAIop of the driving current of the LD 2 is varied and controlled by a control circuit 11. The DELTAIop to be the effective condition of the HFM is varied by the control circuit 11 and the return beam noise being different by the dispersion of the LD 2 is reduced. |
