EFFICIENT OPTICAL PARAMETRIC OSCILLATOR AT 1.6-MU-M

We extend the operating regime of diode-pumped Nd:YAG lasers into the eye-safe region at 1.61-mu-m by using an efficient optical parametric oscillator in KTP. Total energy conversion efficiencies of the 1.06-mu-m pump to 1.61-mu-m signal and 3.1-mu-m idler approach 40%, with 25% conversion to 1.61-mu-m alone. This device has a wallplug efficiency of 0.8%, producing 2.5-mJ output energies at an eye-safe wavelength, and is readily scalable to higher energies.