| 摘要 |
PURPOSE:To enable a laser oscillator to oscillate not only laser rays of fundamental wavelength but also its second harmonic of the same output power as laser rays of fundamental wavelength by a method wherein a second harmonic generating nonlinear crystal is placed in one of resonators which can be switched. CONSTITUTION:If a lambda/2 plate 5 is not inserted into an optical axis, light of fundamental wavelength is amplified in a polarization direction determined by a polarizer 8 between a total reflection mirror 1 and an output mirror 2 penetrating a plate type polarizer 4 and partially projected through the output mirror 2 when a rod 9 serving as oscillation medium is excited. When a lambda/2 plate 5 is inserted into an optical axis, light is changed in polarization direction from P to Q polarization, so that light of fundamental wavelength is totally reflected by the polarizer 4 and amplified between the total reflection mirror 1 and a two-wavelength total reflection mirror 3, the inner power of a resonator is partially converted into second harmonic through a nonlinear optical crystal 7 and projected outside through the polarizer 4. A few % to tens % of the power in a resonator is directly converted into second harmonic and projected outside. |
