| 摘要 |
PURPOSE:To compensate the wave front distortion even for a weak light. CONSTITUTION:When an incident light 1 is reflected by a shape variable mirror 2 to compensate the distortion of a wave front 14, the reflected light is phase modulated by vibrating every region of the reflection surface of the mirror 2 using different frequencies. The phase modulated light is taken out by a beam splitter 3 and converged on a pin hole 7 by a lens 6. The converged light is interfered with a laser beam 11 outputted from a laser oscillator 9 and the light intensity is detected by a photodetector 8. A wave front controller 12 separates each phase modulated signal based on the light intensity, the amount of advance or retard of an actuator placed at each region of the mirror is decided by the signal and the regions are driven through a driving power supply 13. Since the detected each phase modulated signal is an alternating signal, the signal is amplified by the interference with the laser beam and the compensation is made for the distortion of weak light wave front whose intensity is less than the receiving level of the photodetector. |
