Temperature dependences of the refractive indices of a nonlinear LiB3O5 crystal in the THz range
D.M. Ezhov1, D.M. Lubenko2, A.A. Mamrashev3, Yu.M. Andreev1,4
1National Research Tomsk State University, Tomsk, Russia
2High Current Electronics Institute of the Siberian Branch of the RAS, Tomsk, Russia
3Institute of Automation and Electrometry of the Siberian Branch of the RAS, Novosibirsk, Russia
4Institute of Monitoring of Climatic and Ecological Systems of the Siberian Branch of the Russian Academy of Sciences, Tomsk, Russia
Keywords: nonlinear crystal, lithium triborate, THz range, temperature dependence, refractive index, difference frequency generation, birefringence
Abstract
Using nonlinear LBO crystals of 30 × 30 × 10 mm3 in size, the spectral-temperature dependences of refractive indices in the long-wavelength part of the THz range 0.05-0.5 THz are obtained by means of terahertz time-domain spectroscopy under heating from 20 to 200 °C. Intersection of spectral dependences of the refractive index components nx and ny at ~ 84 °C is found. The results can be used for selection of types and phase-matching conditions for frequency conversion into long-wavelength part of the THz range, which is prospective for monitoring the gas composition of the atmosphere due to weak influence of the aerosol attenuation.
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