| 摘要 |
PROBLEM TO BE SOLVED: To provide a wavelength conversion device capable of keeping high efficiency of wavelength conversion for a longer time than that in the prior art. SOLUTION: When performing wavelength conversion of a second harmonic wave L2 in a fourth harmonic wave generating part 14, the incident position of the second harmonic wave L2 is relatively displaced in a direction including a projection direction component C1 of +C axis to the incident plane S1 in a BBO crystal 142 in the incident plane S1. Thereby, for example, when the BBO crystal 142 is deteriorated due to absorption of a fourth harmonic wave L4 in a deep ultraviolet area, the efficiency of wavelength conversion in the fourth harmonic wave generating part 14 is efficiently recovered. COPYRIGHT: (C)2010,JPO&INPIT |
