| 摘要 |
PURPOSE:To prevent the deterioration of stability and control band-with even in the case where the number of light sources increases, by feeding back a signal to a physical quantity for controlling each laser oscillation frequency in a manner in which the signal generating in accordance with the frequency deviation from each peak of transmittance has a minimum value. CONSTITUTION:After each output of semiconductor laser is coupled to a fiber, each of them is coupled to a single fiber with a wave combining device, and said fiber is coupled to a waveguide type ring resonator 31. Frequency- dependency has peaks at an equal frequency interval. Frequencies of laser 21-2n are previously set at the vicinities of peaks P1-Pn. When the frequency interval is DELTAf, the frequency range capable of stabilization is + or -DELTAf/2. The output of a phtodiode 5 which receives the transmitted light is superposed with frequency components F1-Fn. This output is divded into (n) portions which are subjected to mixing with frequencies F1-Fn, by oscillators 11-1n. From the mixed frequencies, low frequency components are extracted through lowpass filters B1-Bn, which are negatively fed back to the bias circuit of each laser. The respective light frequencies of the respective lasers f1-fn can be stabilized at a constant frequency interval. |
