Investigation of Adhesive-free bonded Potassium Titanyl Phosphate crystal based optical parametric oscillator for generation of 2.1 µm wavelength at high repetition rate

In this paper an application of newly available adhesive-free bonded Potassium Titanyl Phosphate crystal is reported. An optical parametric oscillator (OPO) based on a pair of adhesive-free bonded (AFB) Potassium Titanyl Phosphate (KTP) crystals in a walk-off compensated configuration has been demonstrated and investigated. A maximum average output power of 3 W has been achieved at a pulse repetition rate of 10 KHz using Nd:YVO4 as a pump source. The OPO generates near degenerate wavelengths at 2.127 µm and 2.131 µm with a small spectral separation of 4 nm. The results show a highly stable output with a slope efficiency of 23.6% and OPO threshold as low as 32 MW/cm2. The OPO output stability and threshold achieved is significantly better as compared to conventional KTP OPO.