Abstract

We present a highly versatile cavity design for the study of χ⁽²⁾-nonlinear processes. The generation of second harmonic light is demonstrated in a monolithic ring resonator made of MgO:LiNbO₃. It is based on the confinement of the resonator modes by total internal reflection only^l (Fig.1). This concept, named MOTIRR (monolithic total-internal-reflection resonator), provides a passive resonator with minimized losses, because there are only the bulk losses of the nonlinear crystal. Input-and output-coupling is performed by frustrated total internal reflection (FTIR). The possibility to change the “mirror” reflectivities by varying the distance between the coupling prism and the resonator gives high flexiblity. Separate coupling of the orthogonally polarized fundamental and harmonic waves is possible by using birefringent prisms.

© 1993 Optical Society of America