Concise and efficient direct-view generation of arbitrary cylindrical vector beams by a vortex half-wave plate

Abstract

A concise, efficient, and practical direct-view scheme is presented to generate arbitrary cylindrical vector (CV) beams, including CV beams, vortex beams, and cylindrical vector vortex (CVV) beams, by a vortex half-wave plate (VHP). Six kinds of first-order and other high-order CV beams, such as azimuthally polarized (AP) beams, antivortex radial polarization mode beams, and three-order AP beams, are formed by simply rotating a half-wave plate. The Stokes parameters and double-slit interference of multitype CV beams are investigated in detail. The polarization parameters, including degree of polarization, polarization azimuth, and ellipticity, are obtained, which demonstrates the efficient generation of CV beams. In addition, the double-slit interference experiment is introduced in the setup, and fringe misplacement and tilt appear for CVV beams, in which the misplacement number M is 2 P + 1 for P ≤ 2 and 2 P − 1 for P ≥ 3 , where P is the polarization order number, and the fringe tilt offset is positively related to the topological charge number l of CVV beams. In addition, new types of VHPs can be formed by cascading two or more VHPs when the types of available VHPs are limited, assisting in more flexible generation of multitype CV beams. It is experimentally demonstrated that arbitrary CV beams with high quality are effectively achieved by the proposed setup, and the double-slit interference method can be utilized to determine and analyze CV beams rapidly and concisely by practical performance, which shows the potential to be implemented as a commercial device.

Production of orbital angular momentum states of optical vortex beams using a vortex half-wave retarder with double-pass configuration

“…Subsequently, the obtained CP beam is transformed by the VHWR to an optical vortex (OV) with orbital number - or + depending on the input polarization. Behind the VHWR, the Jones vector of the transmitted beam can be expressed as 20 The function for characterizing the spatial distribution involves the OV radius on the -plane. Here, symbolizes the VHWR Jones matrix with fast axis direction at an azimuth angle .…”

“…The angle is related to the VHWR azimuth angle by , where denotes the fast axis direction when 20 . Therefore, using and taking , we can input OAMs wave function into as follows: where is the wave function for OAMs with the topological charge number 54 .…”

“…For the creation of an optical vortex, numerous alternative methods have been reported 7 , 14 , 20 . They can be typically grouped into intra-cavity mode selection and extra-cavity conversion techniques.…”

“…On the other hand, the extra-cavity conversion mean is related to generation of an optical vortex outside the laser cavity using optical elements such as a SLM 26 , 27 , a forked grating 28 , cylindrical lenses 29 , and transmissive programmable metasurfaces 30 . Recently, polarization optics configuration known as a vortex half-wave retarder (VHWR) has been utilized to convert Gaussian laser beams into Laguerre-Gaussian modes with OAM 20 , 31 . Xiujian Li et al illustrated that high-order cylindrical vector beams were realized by cascading multiple VHWRs 32 .…”

Evolution of Pancharatnam-Berry phase on a hybrid-order Poincaré sphere based on vortex half-wave plates

“…Vortex half-wave plate (VHP) is a polarization optical element commonly used to generate cylindrical vector beams [20][21] . VHP has consistent phase retardance  in the whole effective action region, but the direction of its fast axis changes constantly around the center according to certain rules, which can be expressed as…”