Diffraction gratings generating orders with selective states of polarization

Abstract

We propose specially designed double anisotropic polarization diffraction gratings capable of producing a selective number of diffraction orders and with selective different states of polarization. Different polarization diffraction gratings are demonstrated, including linear polarization with horizontal, vertical and ± 45° orientations, and circular R and L polarization outputs. When illuminated with an arbitrary state of polarization, the system acts as a complete polarimeter where the intensities of the diffraction orders allow measurement of the Stokes parameters with a single shot. Experimental proof-of-concept is presented using a parallel-aligned liquid crystal display operating in a double pass architecture.

Vector Beam Polarization State Spectrum Analyzer

“…According to the procedure we described in ref. 17, we design now a vector grating by combining two different phase-only gratings, one affecting the horizontal linear polarization, and another affecting the vertical linear polarization.…”

“…Using our approach for generating q -plates 27 , we make a vector beam diffraction grating that simultaneously creates 6 different vector beams with different charges in the horizontal diffracted orders. In addition, we combine this with a previously reported polarization diffraction grating 17 in the vertical diffracted orders where each order has a different polarization state on the zero-order Poincaré sphere. As a result, we are able to generate, in a single shot, 6 × 6 different vector beams where the horizontal order shows different topological charge, while the vertical order shows different states of polarization.…”

“…The same approach can be applied to design two different phase gratings to be applied to two orthogonal states of polarizations, in order to produce a polarization diffraction grating (PDG) where the state of polarization can be defined at will at each diffraction order 17 .…”

Polarization state generation and measurement with a single metasurface

“…Notably, it allows for the generation of arbitrarily specified polarization states on the diffraction orders and equivalently, polarimetry with an arbitrarily specified set of basis polarizations. We note that a similar approach with similar functionality has been demonstrated using liquid crystal spatial light modulator technology [57,58]. Owing to the constraints of these SLMs, however, a relatively complex double-pass architecture relying on a waveplate and a polarization beamsplitter must be employed in order to impart independent phase profiles on x and y polarized light independently, limiting the scope of potential applications.…”

A Wavefront Division Polarimeter for the Measurements of Solute Concentrations in Solutions

“…Among these wavefront division polarimeters are the four-channel polarimeter and the Azzam’s four detector photomultiplier. Other wavefront division polarimeters are based on gratings [5,7] and on the wavefront division by parallel plane glass plates [5]. …”