Abstract

Recently, conventional optical parametric oscillators (COPO’s) based on quasi-phase matching (QPM) were implemented in LiNbO, [1]. However, CPOP requires a cavity to establish oscillation. Harris [2] introduced the concept of backward OPO’s (BOPO’s) based on conventional phase matching (CPM): a mirror feedback is not required to establish oscillation. However, for the BOPO’s based on the CPM, degenerate BOPO’s are not possible. Most recently, we proposed transversely-pumped counter-propagating OPO’s (TPCOPO’s) due to combination of CPM and QPM [3], TPCOPO’s do not require a mirror to establish oscillation either. On the other hand, recently, GaAs/ AlGaAs multilayers [4] and asymmetric coupled quantum-well domain structures [5] were used to achieve second-harmonic generation (SHG). To achieve QPM, the thickness of each of the multilayers or the domains is half of the SH wavelength in the material. For a conventional second-order nonlinear material such as KTP or LiNbO₃, it can be periodically poled to achieve SHG [6]. The thickness of each domain is usually much larger than the wavelength of the fundamental or SH wave. Here, we present our results of the first feasibility study of the degenerate BOPO’s and backward SHG (BSHG) based on QPM.

© 1996 Optical Society of America