GENERATOR OF FOURTH HARMONIC OF YAG LASER

摘要

PURPOSE:To improve conversion efficiency to fourth harmonics by arranging a second nonlinear type optical element generating fourth harmonics from second harmonics onto the optical path of the resonator of second harmonics. CONSTITUTION:Second harmonics generated from a first nonlinear type optical element 5 resonate while reflecting to both a first mirror 13 and a second mirror 14. A second nonlinear type optical element 6 is disposed at a position on the resonant optical path of the resonant second harmonics, an optical path between a harmonic separator 12 and the second mirror 14. Consequently, all of the light of resonant second harmonics are projected to the second nonlinear type optical element 6, the fourth harmonics of a YAG laser are generated efficiently by a nonlinear type optical effect, and the fourth harmonics are reflected by the harmonic separator 12 and output. Accordingly, conversion efficiency to fourth harmonics can be improved.