Optical parametric oscillator at 1.6 μm based on non-critical phase matching RTP crystal

This paper reports an intra-cavity rubidium titanyl phosphate(RTP) optical parametric oscillator producing the eye-safe light driven by LD end-pumping Nd:YAG laser. A non-critical phase matching RTP crystal with 4 mm4 mm20 mm in size was adopted for nonlinear optics crystal. The signal light output characteristics with different pulse repetition frequencies of Q-switcher were compared. With a diode pump power of 10.5 W and a pulse repetition frequency of 15 kHz, a maximum output power of 900 mW eye-safe laser at 1.62 m were achieved, with a diode to signal conversion efficiency up to 8.6%. The pulse widths for the 1.62 m signal light and 1.06 m fundamental light were about 4.6 and 8.2 ns, respectively. The center wavelength of signal light was about 1618 nm with a line-width less than 0.5 nm.