| 摘要 |
PROBLEM TO BE SOLVED: To eliminate a frequency reference laser device and reduce the size of an equipment, by comparing the frequency of laser light having a specified frequency in correspondence with the quantity of inrush current and the resonance frequency of a fiber ring resonance, and, based on the comparison result, controlling the quantity of the inrush current. SOLUTION: A laser light generating section 2 emits laser light of such an oscillation frequency as to correspond to a value of current IZ. The emitted laser light is branched by means of a fiber coupler 5 into laser light LO and laser light LT, and the laser light LT is put into a fiber ring resonator (resonator) 9. The laser light LT is modulated by a phase modulator 10 in the resonator 9, outputted from a fiber coupler 8 as laser light LZ, inputted into a synchronous detector 16 through a photo detecting circuit 15, and finally is inputted into a frequency controlling circuit 4 as an electric signal CC. The frequency controlling circuit 4 converts the difference between an oscillation frequency of the laser light emitted from the laser light generating section 2 and the resonance frequency of the resonator 9 into current IC, and outputs it to an adder 3 to make the frequency of the laser light LO constant. |
