| 摘要 |
PURPOSE:To stabilize a laser wavelength by arbitrary frequency at a certain fine interval by a method wherein a plurality of mirrors and a PZT are installed, distances among the mirrors are varied, the distances among the mirrors are fixed by control by a known laser, the beams of a tunable laser are projected among the mirrors and the wavelength of the laser beams is controlled so that intensity thereof is maximized. CONSTITUTION:Two plane mirrors or spherical mirrors 3 are separated only by a distance satisfying the conditions of resonance of a wavelength known laser 2 and fixed through a PZT (a rolling element) 4. High-tension DC voltage is applied onto the element 4 by an applying circuit 5, and an AC component is overlapped. The thickness of the element 4, cavity length, is changed at a period (f) by the AC component. Cavity length is displaced only by fine length centering around the length of the conditions of the resonance of laser beams by selecting the voltage of the AC component at a proper value. The displacement is detected by a detector 7, and input to an amplifying and feedback system 9. When the center of cavity length is displaced from the position of the conditions of the resonance of laser beams, approximately linear differential voltage is given by phase sensible detection 10. When the differential voltage is applied to the element 4, a laser wavelength can be conformed to the conditions of the resonance of laser beams 2. |
