Microwave phase conjugation using arrays of nonlinear optically pumped devices

Phase conjugation is a technique for reversing both the direction of propagation and the overall phase factor of an incoming wave. Up to date, most developments have concentrated on the optical regime due to the availability of nonlinear materials and power density restrictions. The extension of phase conjugation techniques to microwave frequencies has been explored using mixing elements with antennas [Cutler et al., 1963]. In this work, we report the use of optical signals as carriers of the microwave pump signal. This optical injection technique is the key to making simple, viable, low cost microwave phase conjugation arrays and nonlinear microwave surfaces