| 摘要 |
PURPOSE:To reduce laser noise on high output power by setting the amplitude of high-frequency output of a high-frequency oscillator to the difference between drive output and the maximum output of this drive output for superposing high-frequency output to the low-frequency drive output. CONSTITUTION:When low-frequency drive output is high, the amplitude of high-frequency current of a high-frequency oscillator is set to the difference between drive current and the maximum current of drive current for superposing high-frequency output on low-frequency drive output. Namely, the high-frequency oscillator 10 generates a high-frequency current with an amplitude controlled by an amplitude controlling device 11, and this high-frequency current is superposed on the DC component of a drive current controlled by an automatic output control circuit 6. thus, by controlling the amplitude of the output of the high-frequency oscillator, it is possible to limit noise faborably by superposing high frequency when the semiconductor laser output is high. |
