Optical Based Electrical Properties of Thiourea Borate NLO Crystal for Electro-Optic Q Switches

Abstract

Optically-based electrical properties such as, electro-optic, dielectric, electric and optical tolerance of thiourea borate, a semi-organic crystal, are examined and reported. The efficient borate family crystal is conveniently grown by a slow evaporation technique. Ultraviolet and visible spectral studies reveal wide transparency in the entire visible and near infrared region. The low cut-off wavelength at 255 nm and high band gap energy at 4.8 eV indicate excellent nonlinear optical characteristics of the grown crystal. Electro-optic properties such as refractive index, the dielectric constant, optical susceptibility, optical polarizability and optical and electrical conductivity are assessed and depicted graphically by an optical method. Dielectric properties such as the dielectric constant and the dielectric loss are analysed for various frequencies and temperatures. AC conductivity, activation energy and Q factor of thiourea borate crystals are presented graphically, and the suitability of the crystal for electro-optic Q switching devices is probed. Optical threshold studies are carried out, and the optical tolerance value is evaluated to be 26 × 10⁻⁴ GW/m².