| 摘要 |
PURPOSE:To suppress mode hopping, by superimposing high frequency pulses, in which at least one of frequency, duty cycle and amplitude is controlled in correspondence with the change in mode, on an applied signal. CONSTITUTION:Light emitted from a semiconductor laser 10 is split by a beam splitter 11. The straightly advancing light is used for controlling the output of a laser printer and the like. The reflected light 13 is received by a spectroscope 14. The single longitudinal oscillating mode of the laser light is detected by the spectroscope 14. The light is converted into a voltage value corresponding to the wavelength of the light by a lambda-V converter 15. In correspondence with the output, a control circuit 16 outputs high frequency pulses, in which at least one of frequency, amplitude and duty cycle is changed. The pulses are superimposed on signal data in a signal data generating part 17. In this constitution, mode hopping is not yielded. |
