Abstract

Nanosecond-pulsed optical parametric oscillator (OPO) devices are versatile sources of tunable coherent radiation,^1,2 but their spectroscopic utility is hindered by a trade-off between spectral bandwidth and complexity. The optical bandwidth of a simple free-running OPO is typically tens of cm⁻¹ and unsuitable for many spectroscopic purposes, whereas narrowband OPO operation often relies on elaborate designs involving intracavity gratings and étalons.² We describe relatively simple procedures enabling control of a continuously tunable ns-pulsed OPO, with effective optical bandwidths ranging (according to spectroscopic application) from several cm⁻¹ (~100 GHz) down to ~0.01 cm⁻¹ (~300 MHz). A particularly novel feature of our OPO-tuning strategies is that, contrary to common practice, we employ passive optical cavities with no need for intracavity wavelength-selective elements or active feedback control of cavity length. Our methods are successfully demonstrated by several applications to atomic and molecular spectroscopy.^1–5

© 1995 Optical Society of America