Second Harmonic of Laser Radiation for IR-Range in Mixed AgGa0.6In0.4Se2 Crystals

The results of investigations of the influence of different parameters on conversion efficiency in mixed AgGa0.6In0.4Se2 crystal in conditions of existing experiments are cited. The angular dispersion coefficients for three versions of crystal AgGaxIn⁡1-xSe2, differing by a content of indium, have been calculated. A comparison was made of the obtained results on conversion efficiency with analogous results in case of other crystals and with corresponding experimentally measured values. The applied analytical method makes it possible to calculate the optimum parameters of both crystal-converter and a source of radiation for conditions of uncritical phase matching in the concrete experiment

Group velocity mismatch at ultrashort electromagnetic pulse propagation in nonlinear metamaterials

The parametric interaction of optical wave pulses in metamaterials is considered in the first approximation of the theory of dispersion. The interaction between the quasi-monochromatic pump wave and the wave pulse at the total frequency with quadratic phase modulation is assumed. The results of calculation of the shape of the spectrum of an excited signal wave at a difference frequency are presented for low frequency pumping. It is shown that the effects of group mismatch in metamaterials lead to a narrowing of the spectrum of the excited wave. With an increase in the modulation degree of a weak exciting wave, the spectrum of the excited wave broadens