OPO Developed for Mid-IR Spectroscopy

Physicists at the University of St. Andrews in St. Andrews, UK, have reported the development of an optical parametric oscillator (OPO) with mid-IR output. The device shows pulse repetition rates of up to 322 MHz and may lead to the development of a source for the time-resolved spectroscopic examination of intersubband transitions, scattering and other phenomena in semiconductors.

The OPO is constructed around a commercially available, mode-locked Ti:sapphire laser that is pumped by a 5-W, frequency-doubled Nd:YVO₄ laser. The laser output is focused on a 6-mm-long crystal of periodically poled LiNbO₃. The device, which was described in the July 24 issue of Applied Physics Letters, displayed a tuning range of 3.9 to 5.98 µm in the idler over a pump tuning range of 835 to 960 nm.