Surface electromagnetic wave propagation on NaClO3 and KTP crystals

Abstract

Sodium chlorate - NaC10, and potassium titanil phosphate - KTiOPO4(KTP) single crystals were studied in the mid infrared (IR) using IRreflectivity, surface polariton (SP) dispersion and surfaceelectromagnetic wave (SEW) measurements.IR reflectivity spectra were measured using Fourier transformspectrometer DA3-36 (BOMEM). From these spectra complex dielectricfunction was calculated using Lorenz oscillators fit (dispersion analysisDA) and Kramers-Kronig method. SP dispersion and SEW complex effectiverefractive index were calculated too. For both crystals in the region ofCO, laser operation SP exist and SEW have measurable propagation length.SP spectra were studied by attenuated total reflection technique usingMichelson-110 (BOMEM) Fourier transform spectrometer.SEW propagation measurements were made using tunable CO, laser.Theradiation of the CO, laser was focused onto the slit between the samplebeing investigated and the screen placed at a distance of the order ofthe wavelength from the sample. A part of radiation is transformed intoa SEW which propagates along the surface and converts into a bulk wave atthe edge of the sample. This wave interferes with the bulk wavediffracted at the exciting aperture. The interference pattern is recordedby a pyroelectric detector which is uniformly moving along the arc withthe slit as center. The angular positions of the extrema T. of the orderof m/2 are determined by