Optical properties of chalcogenide glasses in the terahertz spectral region

Optical properties of chalcogenide glasses of three different compositions (As₂S₃, As₂S₃ × As₂Se₃, and As₂Se₃) are studied via terahertz pulsed spectroscopy. Absorption coefficients and refractive indices are measured in a frequency range of 0.2–1.6 THz. The results show that the phonon modes of the studied materials vary with the composition of the glasses.     

Anomalous Ortho-to-Para Ratio of Nuclear Spin Isomers of H2O at Low Temperatures

A theoretical model proposed for nuclear spin isomers of H₂O molecules located inside the C₆₀ fullerene explains an anomalously high stability of ortho-H₂O isomers detected in the experiments reported in [B. Meier et al., Nature Commun. 6, 8112 (2015)] at a temperature of T = 5 K.

     

Acceleration of the Conversion of Nuclear Spin Isomers of Water Molecules under Their Vibrational Excitation

JETP Letters - Water molecules exist in nature in the form of nuclear spin isomers ortho-H2O and para-H2O with the total spin of hydrogen nuclei I = 1 and 0, respectively. The effect of the...     

Optical Properties and Terahertz Radiation Generation in a LI2B4O7 Crystal

Russian Physics Journal - Spectral dependences of components of the refractive index and absorption coefficient in a Li2B4O7 (LB4) nonlinear crystal are determined in the THz range for the first...