Diode-pumped passively Q-Switched intracavity OPO with a folded cavity configuration

摘要

We present in this report an efficient KTP-based intracavity optical parametric oscillator driven by a diode-pumped Nd:GdVO_4/Cr:YAG passively Q-switched laser. For the first time, a novel folded cavity configuration was employed to set the KTP and Cr:YAG crystals separately at different fundamental beam waists. Based on the ABCD-matrix theory and by taking the thermal lens effect into account, the laser cavity was well optimized to enhance the OPO performance. A diode pump threshold as low as 1.2 W and a maximum signal (1.57 μm) average output power up to 560 mW have been achieved. Efficient energy transfer in the IOPO leads to short pulse duration (1.8-2.6 ns) and high peak power (6.8 kW) output at 1.57 μm. Additionally, the correlation dynamics between the pump laser and the OPO was analyzed in detail.