| 摘要 |
PROBLEM TO BE SOLVED: To provide a light frequency selecting device which can be applied to a system having a wavelength converter (frequency shifter). SOLUTION: This device is constituted of a signal light source 1 outputting signal light, the frequency shifter 2 outputting conversion signal light, an optical filter 51, a photodetector 4, an oscillator 5 outputting a low frequency signal, a modulation means 6 modulating the light source 1 in terms of frequency based on the signal from the oscillator 5, a synchronous detention means 7, an inversion means 8 inverting the output characteristic of the means 7, and a control means 53 controlling the filter 51 based on output from the means 7. |
