Gildardo-Pablo Lemus-Alonso

In this work, we propose a very simple, and efficient interferometric setup for transforming a homogeneous linearly polarized beam into a radially polarized beam. The proposal is based in a double-aperture common-path interferometer adapted for phase-shifting of π radians per quadrant. It is carried out by placing two composed grating in each aperture, which are built by joining two gratings displaced by a half-period, on horizontal and vertical direction, respectively. The input optical beams are orthogonal and linearly polarized, and their amplitudes are modulated in quadrature. We show that the combination of amplitude-only filters and the π phase-shifting per quadrant can achieve the implementation of complex filters such as the sinusoidal ones. The combination of the spatial modulation of both amplitude and phase generates an optical field with radial polarization. Specialized optical elements of high cost and SLM devices are avoided. We show the theoretical model and experimental results.

This paper presents a novel, simple, robust, and very stable polarimeter which is able to measure in a single-shot the state of polarization (SOP) of an optical field. In this proposal, an optical field with an unknown SOP and an optical field with a reference SOP are superposed by using a double aperture common-path interferometer (DACPI), obtaining two interferograms with adjustable carrier frequency in a single shot. Each interferogram has different visibility and phase-step where the information of the unknown SOP is contained. It is shown that under a typical Fourier analysis any SOP can be successfully measured without the necessity of knowing the carrier frequency. The present proposal is justified mathematically and probed experimentally.