Microwave-induced optical non-linearity of amino acid crystals

Abstract

Changes (ΔR) of amino acid crystals infrared (IR) reflectance (R) induced by simultaneous irradiation of IR and microwaves (MW) or extremely high frequency (EHF) radiation have been observed. It was shown that under the microwave action, components of dielectric permeability tensor, εij, which is responsible for the alteration of the R, are changed. Square dependence of ΔR/R on power of EHF radiation has been observed. An attempt for explanation of the observed effect as non-linear phenomenon with participation of two EHF photons (Ωm) and one IR photon (ωi) was made. The estimation shows that the third order non-linear polarizability coefficient, χ⁽³⁾(Ωm,-Ωm, ωi), reaches the gigantic value - 10 сm/erg for α-Gly single crystal.