Abstract

Periodically poled lithium niobate (PPLN) has recently emerged as an attractive material for high gain, low pulse energy OPOs for spectroscopy and DIAL remote sensing applications. In many cases, narrowband or single mode operation is required, but pulsed ns OPOs exhibit broad free-running optical bandwidths, especially when operating near degeneracy. Here we report on OPOs in a grazing incidence (GI) configuration. These devices generate efficient, single axial mode, near tem₀₀ output and offer a number of advantages over recently reported single mode PPLN OPOs^1,2 incorporating injection seeding or intra-cavity étalons The GI OPO is a simple, compact device capable of emitting single mode radiation throughout the full tuning range of the OPO. It dispenses with the cost, complexity and limited tuning of seeded systems. Intra-cavity etalons tend to preclude simultaneous signal and idler output, as well as single mode operation close to degeneracy. In the GI cavity, high loss - which limits the performance of KTP and BBO GI OPOS - is offset by the substantially higher gain in PPLN.

© 2000 IEEE