SECOND HARMONIC GENERATION DEVICE AND METHOD FOR CONTROLLING TEMPERATURE IN SECOND HARMONIC GENERATION DEVICE

摘要

PROBLEM TO BE SOLVED: To improve efficiency of conversion to a second harmonic with an SHG element while avoiding the necessity for highly accurately controlling temperature.;SOLUTION: In a second harmonic generation device equipped with the SHG element 55 to generate the second harmonic of an incident laser beam and a temperature controlling means TS to control temperature of the SHG element 55, the temperature controlling means TS is constructed so as to make the degree of heating or cooling on both end parts and on the intermediate part of the SHG element 55 in a light propagating direction different from each other. Thereby even when an optical path length of the SHG element is not so long, the temperature distribution in the light propagating direction is uniformized to the temperature to maintain the efficiency of conversion to the second harmonic at a highly efficient level.;COPYRIGHT: (C)2004,JPO