LASER WAVELENGTH CONVERTER

摘要

A nonlinear optical crystal element (21) for wavelength conversion is surrounded by a heat sink (22) having cooling fins (23a, 23b, 23c). Cartridge heaters (24) are arranged on the heat sink (22) to heat the nonlinear optical crystal element (21) evenly, and the temperature is adjusted by a heater controller (30). Laser radiation is incident on the nonlinear optic element (21), which converts wavelength to produce radiation of a shorter wavelength. When the repetition frequency of the laser radiation is high, the heaters (24) are not energized and heat is removed by the heat sink (22). When the repetition frequency of the laser radiation is low, on the other hand, the heater (24) is energized to maintain the temperature of the nonlinear optical crystal element (21) so that conversion efficiency may improve.