Theoretical study and 2D computational modeling of middle-infrared radiation generation in the field of few-cycle laser pulse propagating in GaSe slab waveguide

We have performed the theoretical study and 2D finite-difference time-domain-based computational modeling of middle-infrared radiation generation in the field of few-cycle laser pulse propagating in GaSe slab waveguide. The interaction of linearly polarized pulse with 1.98 um central wavelength, 22.44 fs duration, and electric field amplitudes 100 MV/m, propagated along the 010] crystalline direction of GaSe crystal with polarization aligned along 100] is considered. The crystal length chosen is equal to 21.78 um. Symmetric GaSe slab waveguides with 6.336 um, 7.92 um, 11.88 um, and 15.84 um thicknesses excited by the Gaussian pump beams with 3.96 um, 5.94 um, 8.91 um, and 11.88 um diameters, respectively, are considered. The 2D distributions of the electric fields are obtained by numerical integration of Maxwell’s equations’ systems. The spatially spectral normalized distributions of the electric fields are obtained. The efficiency of generated infrared (IR) radiation vs. spatial transverse coordinate is obtained.