| 摘要 |
PURPOSE:To enhance conversion efficiency to second harmonic by providing a nonlinear optical crystal and subjecting the laser oscillation light of a solid- state laser to multiple reflection. CONSTITUTION:A nonlinear optical crystal 4 is disposed in a state inclined with respect to the optical axis of the laser oscillation light of a solid state laser, and a basic wave omega (laser oscillation light of a solid state laser) generated in a resonator is introduced into a crystal through a reflection preventive film 11. Here, omega is the frequency of light. The crystal is so cut in a crystal orientation as to enhance the nonlinear optical effect in the propagating direction of a basic frequency omega in the crystal, thereby regulating the inclining angle. The omega light in the crystal is multiple reflected in the crystal via high reflecting films 10, 10' while converting the part into secondary harmonic waves 2omega, emitted from a reflection preventive film 11', and emitted laser light 7 is output via an output mirror 5 for the resonator. Thus, the more the number of the reflections is large, the longer the crystal length equivalently becomes, thereby enhancing the conversion efficiency of the secondary harmonic wave. |
