Generation of the wave by compensation of phase shift of propagation of waves in a non linear optical medium

摘要

In a nonlinear optical medium (m), such as gallium arsenide, two (or a) collinear incident monochromatic waves (o1, o2) are injected in order to generate a (or two monochromatic wave (o3)). The medium induced between the three waves a propagation phase-shift of pi if the waves travel along a length of coherence and compensated at 0 modulo 2pi each time that the waves which have travelled a periodic distance (d) in the medium. In order to increase considerably the conversion efficiency, the periodic distance between two successive bounces of internal total reflection (r) - zig zag of the waves is strictly less than the length of coherence. The high conversion efficiency over a length of a material which is very short rise to produce coherent optical sources of high power, in particular to wavelengths of 10 μm approximately.