Snapshot polarimeter based on the conical refraction phenomenon

A. PEINADO; A.LIZANA; A. TURPÍN; I. ESTEVEZ; C. IEMMI; T. KALKANDJIEV; J. MOMPART; J. CAMPOS

Munich

Congreso; Modeling aspects in Optical Metrology; 2015

SPIE

A complete and punctual Stokes polarimeter based on the conical refraction (CR) phenomenon is presented. The CRphenomenon occurs when light travels along one of the optical axes of a biaxial crystal (BC), leading to a bright ring oflight at the focal plane of the system. We propose using the connection between the intensity pattern of the CR ring andthe state of polarization (SOP) of the incident beam as a new tool for polarization metrology. In order to implement acomplete polarimeter, the instrument is designed with a beam splitter and two BCs, one BC for each sub-beam. In thesecond sub-beam, a retarder is introduced before the BC, allowing us to measure the ellipticity content of the input SOP.The CR-based polarimeter presents several appealing features compared to standard polarimeters. To name some ofthem, CR polarimeters retrieve the SOP of an input beam with a single snapshot measurement, allow for substantiallyenhancing the data redundancy without increasing measuring time, and avoid instrumental errors related to rotatingelements or active polarization devices.This work shows the instrument design, in particular the parameters of the set-up have been optimized in order to reducethe amplification of noise. Then, the experimental implementation of the instrument is detailed, including theexperimental calibration of the system. Finally, the implemented polarimeter is experimentally tested by measuringdifferent SOPs, including fully and partially polarized light.