| 摘要 |
PURPOSE:To eliminate no satisfaction of phase matching condition due to vibration, heat generated during the operation of a device by so relatively varying an incident angle to harmonic wave generating means of laser light that the conversion efficiency of a harmonic wave becomes a predetermined state. CONSTITUTION:A luminous flux generated from a laser light source 1 is separated by a spectral element 2, emitted to a nonlinear optical crystal 4, thereby generating a second harmonic wave. In this case, part of basic wave light before entering the crystal 4 is separated by a beam splitter 3, and its quantity is detected by a photodetector 17. Part of the reflected harmonic light of the luminous flux passed through the crystal 4 is branched by a beam splitter 6, and its quantity is detected by a photodetector 18. Information of the quantities detected by the photodetectors 17, 18 is sent to a nonlinear optical crystal controller 19 to obtain the ratio of the two quantities, i.e., the harmonic wave conversion efficiency of the crystal 4. The incident angle of the harmonic light to the crystal 4 is regulated by the controller 19 so that the obtained efficiency becomes maximum. |
