| 摘要 |
PURPOSE:To obtain stable output for a long term, by using second harmonic laser light led-out from a reflecting means, and controlling the output of a laser light source for generating fundamental laser light. CONSTITUTION:The pumping laser light outputted from a laser diode 1 is converged by a lens 2 and made to enter laser medium 4 using, e.g. Nd:YAG, via a quater-wavelength plate 3. The laser medium 4 generates fundamental laser light in response to the incidense of the pumping light. A plane mirror 5 and reflecting mirrors 5R and 6R of a concave mirror 6 are arranged so as to bend the optical path in a resonator, thereby attenuating the effective reflectivity. Hence intensity change is restrained, and the forward effective output is made coincide with the backward output, which is led out from a reflecting surface 7R constituting the resonator and detected by a photo detector 8. According to the detected signal, a control circuit 9 controls the output of a laser light source generating the fundamental laser light. Thus the light intensity of effective output is controlled to be constant, and stable second harmonic laser light can be outputted for a long term. |
