Anisotropy of the velocity space of electromagnetic radiation in a moving medium

Abstract

Anisotropy arising in moving media is considered. In these media, the phase velocity of light nonlinearly depends on the velocity vector field of the medium due to anisotropic binding forces between lattice atoms. Observations of the optical anisotropy of light in a rotating optically transparent medium are discussed. Laser radiation with wavelength λ = 0.632991 ± 1 × 10−7 μm propagating in an interferometer was passed through a rotating optical disk D = 62 mm in diameter. The projection of the beam’s path length in the medium onto the flat surface of the disk is l = 41 mm; the refractive index of the glass and its thickness are, respectively, n = 1.71250 for λ = 632.8 nm and 10 mm; and the angle of incidence of the beam on the flat surface of the disk is l0 = 60°. The optical disk is rotated in two directions, and its rotation frequency may reach 250 Hz. Experimental data confirm the linear dependence of the fringe shift on the velocity of the medium up to 29.6 m/s. The measurement accuracy is sufficient to detect angular variations δΔ = 3 × 10−5 in the position of fringes at a fixed rotation velocity of the optical disk.