Narrow-linewidth optical parametric oscillator with an intracavity laser gain element

A demonstration of an optical parametric oscillator and a high-gain laser element operating simultaneously in a common cavity is presented. In such a cavity the signal photons are amplified both in the gain medium and in the nonlinear crystal, whereas the idler photons are generated only in the crystal. The high gain in the laser element reduces the pump threshold for the parametric oscillations. This combined configuration is an efficient, compact design that permits the construction of a tunable source with low pump threshold and narrow linewidth, attained by a wavelength-selective element in the cavity.