Optical sharper focusing in an anisotropic crystal

Abstract

Optical super-resolution technique through tight focusing is a widely used technique to image material samples with anisotropic optical properties. The knowledge of the field distribution of a tightly focused beam in anisotropic media is both scientifically interesting and technologically important. In this paper, the optical properties of a uniaxial crystal with the optic axis perpendicular to the interface under a tight focusing configuration are studied with rigorous theoretical and numerical analysis. The significant effect of the Poynting vector on the focal position introduces an obvious displacement of the focal spot formed by the extraordinary waves (e-ray). Moreover, a sharper focus with a lateral size of 0.22λ is obtained as a result of the effective separation of the ordinary waves (o-ray) and the e-ray. It provides a new tool to fabricate optical structures with higher resolutions than that in an isotropic medium through the far-field method.

All-optical helicity-dependent magnetic switching by first-order azimuthally polarized vortex beams

“…According to the Debye diffraction theory, [27][28][29][30] the focal electric fields of FAPV beams can be expressed as…”

Tight Focusing Properties of Circularly Polarized Annular Multi-Gaussian Beam through a Uniaxial Birefringent Crystal

“…However, fabricating those physical masks are difficult and their efficiency is also low. On the other hand, optically, uniaxial crystals are performing the same operations without additional devices [19]. Alejo and Deng, et al studied the properties of light beams propagating in birefringent material [20,21].…”

Enhancement of Optical Spin-Orbit Coupling in Anisotropic ENZ Metamaterials

“…Due to the complex balance of the electric field components in VVBs, strong focusing [13], [14], [15], [16] or anisotropic media [17], [18], [19] can be used to manipulate the beam polarisation properties by differently influencing the transverse and longitudinal field components. In this respect, hyperbolic metamaterials [20], [21], which exhibit record optical anisotropy since they behave as a dielectric (Re( ) > 0) for one polarisation of light and as a metal (Re( ) < 0) for the other [22], [23], [24], [25], provide unique opportunities for manipulation of VVBs and spin-orbit coupling.…”