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 optical parametric oscillators and amplifiers. By changing the incident angle of the pump beam, one can tune the output frequency in a large range. For the optimal semiconductor structure and with the presence of the horizontal and vertical cavities, the threshold pump powers for the oscillation can be as low as ~100 μW. There is no threshold for amplifying the incident beam. Combining the oscillators or amplifiers with vertical-cavity surface-emitting lasers, it is feasible for us to implement compact and efficient electrically-pumped mid-infrared light sources or amplifiers. The quasiphase matching is achieved by spatially modulating second-order susceptibility along the growth direction based on semiconductor alternating thin layers or asymmetric quantum well domain structures