Analysis of simultaneous Q-switching and frequency doubling in KTP

Simultaneous Q-switching and second harmonic generation in KTP is analysed numerically. In this mode of operation, the phase matching condition for second harmonic generation and the half-wave voltage for Q-switching are interrelated. In this paper, this coupled numerical problem is solved iteratively until a self-consistent solution is obtained. The effective refractive index and effective electro-optical coefficient along the phase matching direction are defined and calculated in order to estimate the half-wave voltage for Q-switching with KTP. Additionally, the application of temperature and wavelength dispersion tuning to compensate for the constant retardation in this biaxial crystal is also studied. It is found that the operating temperature of the KTP crystal should be stable to within 0.1 degrees C for exact retardation compensation.