OPTICAL AND PHYSICAL METHODS OF RESEARCH AND MEASUREMENTS
D. S. Gribanov1,2,3, N. D. Osintseva2, S. L. Mikerin1, N. A. Nikolaev1,3
1Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
2Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
3Novosibirsk State University, Novosibirsk, Russia
Keywords: indium-tin oxide, ITO, terahertz radiation, dielectric permittivity, Drude model, thermo-optic effects, thermal conductivity coefficient, Novosibirsk free electron laser
Abstract
In this work, the interaction of terahertz radiation with thin ITO films (< 300 nm) deposited on fused silica substrates was studied. The complex refractive index of the films was measured in the range of 0.2-1.2 THz. It was found that the Drude model accurately describes the dielectric properties of the films in this region. The parameters of the model were determined by fitting the experimental data across a wide spectral range, from millimeter to visible wavelengths. A linear correlation between conductivity and thickness of the film was revealed. The result is valuable for the design of antireflective coatings for terahertz radiation applications. The studies on the effects of intense terahertz radiation with peak and average intensities of up to 2 MW/cm2 and 1.2 kW/cm2, respectively, showed the absence of laser-induced damage to the films and made it possible to outline the scope of ITO films' application as dichroic mirrors in transport channels for intense terahertz beams.
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