Optical sensing of polarisation using conical diffraction phenomenon

A KGd(WO4)2 crystal has been used as the central piece of a prototype novel optical sensor to identify the plane of polarisation of a beam of light. The device identified the plane of polarisation of the incident beam of light and was found to be accurate to within ±40, comparable to the common polariser-analyser based setup in use in many labs. In order to test a practical application, a polarimetry test was carried out to identify the angle of rotation caused by optically active liquids, showing excellent agreement between the expected values and those measured using the conical diffraction phenomenon. The prototype provides an easy to use tool for fast and effective analysis of linear polarisation for practical applications.