TRANSVERSELY-PUMPED COUNTER-PROPAGATING OPTICAL PARAMETRIC OSCILLATORS AND AMPLIFIERS - CONVERSION EFFICIENCIES AND TUNING RANGES

We show that the second-order optical nonlinearities in the waveguides can be used to implement transversely-pumped counter-propagating opti cal parametric oscillators and amplifiers, By changing the incident an gle of the pump beam, one can tune the output frequency in a large ran ge, For the optimal semiconductor structure and with the presence of t he horizontal and vertical cavities, the threshold pump powers for the oscillation can be as low as similar to 100 mu W. There is no thresho ld for amplifying the incident beam, Combining the oscillators or ampl ifiers with vertical-cavity surface-emitting lasers, it is feasible fo r us to implement compact and efficient electrically-pumped midinfrare d light sources or amplifiers, The quasiphase matching is achieved by spatially modulating second-order susceptibility along the growth dire ction based on semiconductor alternating thin layers or asymmetric qua ntum-well domain structures.