Design of compatible harmonic generation system for multi wavelength and multiple pulse-width laser output

By comparing and analyzing various frequency conversion schemes, a compatible harmonic generation system has been designed. With type-Ⅱ-type-Ⅱ crystal combination configuration, polarization mismatch third harmonic generation and type-Ⅱ orthogonal quadrate second harmonic generation can be quickly switched. The thicknesses were optimized to be 10mm for both crystals by numerical simulation method, as a result, the requirements of high efficiency for long pulse with low intensity, as well as high stability for short pulse with high intensity, can be satisfied.