Theoretical investigation of phase-mismatched second-harmonic conversion efficiency in BBO crystal

We report a modified general relation of nanosecond second harmonic conversion efficiency relation to determine efficiency at any value of power density, laser wavelength, crystal length and beam divergence when transmission value are relative high >90%, which make it a reference for practical study comparison. We apply this study on BBO crystal and study the efficiency as function of both crystal length (0-0.7 cm) and laser wavelength (460-1400 nm), (527-1400 nm) in 3-D plot for phase matching types I and II respectively. Finally, we study the effect of crystal length and power density at generated deep-ultraviolet cut-off type I wavelength 205 nm.