Focusing of Gaussian beam passed under small angle to optical axis of uniaxial crystal

Abstract

We showed both experimentally and analytically, the effect of focusing of a Gaussian beam propagated under small angle ϕ with respect to the optical axis of a uniaxial crystal, on the generation of a bottle beam. At ϕ = 0° two foci that correspond to ordinary and extraordinary parts of a beam form a closed 3D structure of a bottle beam. At this point, the beam, in the foci points, has radially and azimuthally aligned polarizations. Increasing the value of ϕ leads to dramatic changes in the intensity and polarization structure of a bottle beam. Starting from the value of ϕ = ±2° the closed 3D symmetric structure of a bottle beam breaks down. At ϕ = ±5° both beams are focused at the same transverse plane, while its polarization evolves to x- and y-linear. With a further increase in angle ϕ two foci ‘switch’ their spatial positions and move further away.

Propagation of a Pearcey beam in uniaxial crystals

“…[15,16] In reality, crystals play an important part in the design of optical devices, e.g., polarizers and compensators, because of their ability to affect the polarization state of light. [17] Through uni-axial crystals, the propagation of the Airy beam, [18] the Gaussian beam, [19] and the Bessel beam [20] have been investigated. Yu et al have studied the analytical propagation of the finite energy Airy-Hermite-Gaussian beam propagating in a uniaxial crystal orthogonal to the optical axis.…”