Open AccessDispersion properties of sulfur doped gallium selenide crystals studied by THz TDS
Author(s) -
Mira Naftaly,
J. F. Molloy,
Yu. A. Andreev,
К. А. Кох,
Г. В. Ланский,
V. A. Svetlichnyi
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.032820
Subject(s) - terahertz radiation , dispersion (optics) , optics , materials science , refractive index , doping , nonlinear optics , terahertz spectroscopy and technology , gallium , optoelectronics , physics , laser , metallurgy
High optical quality nonlinear crystals of solid solution GaSe(1-x)S(x), x=0, 0.05, 0.11, 0.22, 0.29, 0.44, 1 were grown by modified Bridgman method with heat field rotation. Ordinary and extraordinary wave dispersion was studied in detail as a function of sulfur content by terahertz time-domain spectroscopy (THz TDS) in the 0.3-4 THz range using cleaved and processed (cut and polished) crystals. Suitable dispersion equations for different parts of the entire transparency range were derived, utilizing comparative analyses of the measured data, the available published data, and approximations in the form of Sellmeier equations. A criterion was proposed for selecting measurement results of adequate quality, based on the etalon patterns in the transmission spectrum.