A 1.4–4-μm high-energy angle-tuned LiNbO3 parametric oscillator

We have operated a high-gain angle-tuned singly resonant LiNbO3 parametric oscillator pumped directly at 1.06 μm by a Q -switched Nd:YAG laser. The oscillator angle tunes from degeneracy and operates over the entire 1.4–4.4-μm range. Output energies of greater than 1 mJ/pulse at 5 pps have been observed with a 15% energy conversion efficiency. The key to this device is the large LiNbO3 crystals fabricated from new [01.4] grown boules. Crystals up to 15 mm in diameter and 5 cm in length have been cut at the nominal 47° orientation. These crystals will potentially handle over 2 J of optical energy at 1.06 μm.