Radially Polarized Conical Beam from an Embedded Etched Fiber

利用刻蚀锥形光纤实现与砷化镓纳米波导及谐振器的高效光耦合

Efficient optical coupling to gallium arsenide nano-waveguides and resonators with etched conical fibers

本文提出利用刻蚀锥形光纤实现与砷化镓纳米光子结构的高效光耦合，该方法在低温振动等苛刻环境及多波段下均表现出高稳定性和耦合效率，为受限环境下的量子光学与传感实验提供了新方案。

On-chip radially and azimuthally polarized vortex beam generation utilizing shallow-etched gratings

Cylindrical vector vortex (CVV) beams, complex light fields that exhibit a vector nature and carry quantized orbital angular momentum states, have been widely investigated due to their rich applications. Current technologies to generate CVV beams using individual polarization and spatial phase manipulations suffer from bulky size and low configurability. In this work, we propose and experimentally demonstrate an approach to generate CVV beams with an integrated device based on silicon nitride microring resonator and embedded top-gratings. The device is capable of generating broad-band radially…

Propagation dynamics of vortices in Helico-Conical optical beams

We present the dynamics of optical vortices (OVs) that came from the propagation of helico-conical optical beam. This dynamics is investigated numerically by tracking the OVs at several distances using rigorous scalar diffraction theory. To ensure that our numerical calculations are correct, we compare the intensity profiles and their corresponding interferograms taken at different propagation distances between simulations and experiments. We observe that the peripheral isopolar vortices transport radially inward, toward the optical axis along the transverse spatial space as the beam propagate…

The fine structure of the vortex-beams in the biaxial and biaxially-induced birefringent media caused by the conical diffraction

We consider the paraxial propagation of nondiffracting singular beams inside natural biaxial and biaxially-induced birefringent media in vicinity of one of the optical axes in terms of eigenmode vortex-beams, whose angular momentum does not change upon propagation. We have predicted a series of new optical effects in the natural biaxial crystals such as the stable propagation of vector singular beams bearing the coupled optical vortices with fractional topological charges, the conversion of the zero-order Bessel beam with a uniformly distributed linear polarization into the radially-, azimutha…

Experimental measurement of the self-healing of the spatially inhomogeneous states of polarization of radially and azimuthally polarized vector Bessel beams

We experimentally measured the self-healing of the spatially inhomogeneous states of polarization of radial and azimuthal polarized vector Bessel beams. Radial and azimuthal polarized vector Bessel beams were generated via a digital version of Durnin's method, using a spatial light modulator in concert with a liquid crystal $q$-plate. As a proof of principle, their intensities and spatially inhomogeneous states of polarization were measured using Stokes polarimetry as they propagated through two disparate obstructions. It was found, similar to their intensities, the spatially inhomogeneous sta…

Transformation of vector beams with radial and azimuthal polarizations in biaxial crystals

We present both experimentally and theoretically the transformation of radially and azimuthally polarized vector beams when they propagate through a biaxial crystal and are transformed by the conical refraction phenomenon. We show that, at the focal plane, the transverse pattern is formed by a ring-like light structure with an azimuthal node, being this node found at diametrically opposite points of the ring for radial/azimuthal polarizations. We also prove that the state of polarization of the transformed beams is conical refraction-like, i.e. that every two diametrically opposite points of t…