| 摘要 |
PURPOSE:To make it possible to obtain stably second high-output harmonic light by a method wherein the temperature of an anisotropic solid laser crystal is adjusted in such a way that the laser crystal is formed into a lambda/4 plate of the wavelength of a fundamental wave laser beam. CONSTITUTION:An Nd:YVO4 crystal 5 is held by a metallic holder 8 and the magnetic declination phi of the crystal 5 to a KTP crystal 6 is fixed at 45 deg.. A Peltier element 7 is adhered to the holder 8 and a thermistor 9 for temperature detection is built in the holder 8. The element 7 is driven by a control circuit 10 on the basis of a signal from the thermistor 9 and the crystal 5 is held at a constant temperature. The retardation of the crystal 5 is measured according to the strength of input of excitation light, the retardation is made to store in the circuit 10 as a calibration curve and the temperature of the crystal 5 is automatically set at such a temperature that the crystal 5 is formed into a lambda/4 plate of the wavelength of a fundamental wave laser beam. Thereby, second high-output and low-noise harmonic light can be stably obtained. |
