| 摘要 |
PROBLEM TO BE SOLVED: To stabilize the frequency of the light output signal of a light source used for optical wavelength multiplex transmission, etc. SOLUTION: A branched optical signal 1 from an optical transmission line, etc., is coupled with a waveguide optical frequency discriminator 2, having a peculiar peak characteristic, and an optical receiver 3 and a differentiation circuit 4 generate an error signal between a peak frequency and the frequency of the signal 1, based on the light output of the discriminator 2. Then a waveguide control circuit 5 controls the characteristic of the discriminator 2, so that the peak frequency the frequency of the signal 1. For a light source 9 which generates an inserted optical signal 11, on matches the other hand, part of the light output of the light source 9 is coupled with the discriminator 2 and an optical receiver 6, a differentiation circuit 7, and an optical drive circuit 8 controls the light source 9 through a negative feedback, so that the frequency of the light output of the light source 9 matches this peak frequency. |
