| 摘要 |
PURPOSE:To set the length of a resonator, which is kept constant, at an arbitrary point, by applying perturbation, whose speed is less than a constant value. CONSTITUTION:A second resonator-length control system comprises a comparator 11, a flip-flop 12, a perturbation-direction determining circuit 7 and a perturbation applying circuit 8. The fact that the length of the resonator is kept constant by a first resonator-length control system is confirmed, and operation is started. Perturbation, by which the resonator length is gradually increased by the heat generated by a discharge tube, is applied. With respect to the negative perturbation, the sign is determined by the perturbation-direction determining circuit 7. A signal, which is outputted from the perturbation applying circuit 6, is additionally applied to an additive amplifier 5. The resonator length is gradually increased. The signal of light intensity passes the maximum point and minimum point. The flip-flop 12 is operated at this time, and the positive and negative signs of the perturbation-direction determining circuit 7 are reversed. A reversing amplifier 10 is inserted into the first resonator-length control system by using a signal switching circuit 13, and the output of the amplifier is reversed. Thus the instability of the system is prevented. |
