Abstract

Intracavity optical parametric oscillators (IOPO) offer high conversion efficiencies and shortening of signal pulse duration with respect to performance at pump wavelength [1]. The 0.16 mJ with 1.6 ns pulse duration at 1572 nm was demonstrated in IOPO in passively Q-switched Nd:YAG laser end-pumped by 80 W quasi-cw diode array [2].We demonstrate IOPO in passively Q-switched Nd:YAG slab laser pumped by 300 W quasi-cw diode array SDL 3251-A3 (Fig. 1). Applying the same pump unit in optimised Nd:YAG slab laser with Cr⁴⁺:YAG passive Q-switch it was achieved up to 5 mJ with peak power of 0.5 MW [3]. In the 200 mm long cavity arranged for IOPO it was obtained 1.9 mJ energy in fundamental mode at 1064 nm with 20 ns pulse duration in passive Q-switching regime. The KTP crystal, 5×5×20 mm, x-cut for non-critically phase-matched parametric generation at the signal wavelength of 1572 nm, was used in experiments. The OPO cavity length was 25 mm with flat M₁ mirror of 100% reflection on signal and AR at pump wavelengths.

© 2001 EPS