Quasi-phase-matched sum-frequency generation in layered structures

A theory has been developed for quasi-phase-matched generation of a wave at a sum-frequency within a constant-intensity approximation. In contrast to a constant-field approximation, the constant-intensity approach has been found to give an optimum pump intensity value at which the conversion efficiency reaches its maximum. Analytical expressions have been derived for optimal values of the problem’s parameters. Ways to enhance the power of the coherent optical radiation are shown and analyzed. This will make it possible, in particular, to increase the power in an RGB-source color for which the sum-frequency generation is responsible.