Phase conjugation of planar guided waves

Abstract

Four-wave mixing and two-dimensional phase conjugation of planar guided waves in dielectric–nonlinear dielectric–metal or dielectric–nonlinear dielectric–dielectric structures is considered, and the expression for the phase-conjugate gain is derived. The effectiveness of the nonlinear polarization, with different vectorial structure and different intensity distribution from those of generated phase-conjugate wave, is evaluated by considering the energy balance. Formulas for phase-conjugate gain are given for various wavelengths and for various guiding modes. Also, the dependence of the phase-conjugate gain on the crossing angle between pump beams and the probe beam is analyzed. By model calculation it is shown that the relative effective gain is large for TE modes with dielectric substrates but is small for TM modes with metal substrates.