| 摘要 |
PROBLEM TO BE SOLVED: To maintain high wavelength conversion efficiency of laser light in a vacuum ultraviolet range for a long period. SOLUTION: Nonlinear optical crystal 1a of the laser wavelength converting device 100 is mounted on a movable part 12a of an X stage 12 and moved reciprocally across the incidence optical path of laser light 4a. Consequently, while the laser light 4a is made incident on the nonlinear optical crystal 1a and wavelength conversion is performed so as to obtain laser light 4a', the nonlinear optical crystal 1a moves reciprocally in the X direction crossing the optical path. Therefore, the part of the nonlinear optical crystal 1a through which the laser 4a travels moves with the time, so the self-heating of the nonlinear optical crystal 1a is relaxed a part in the nonlinear optical crystal 1a which possibly deteriorates is widely dispersed, so the nonlinear crystal 1a barely deteriorates, so that high wavelength conversion efficiency can be maintained for a long period. |
