polariser


polariser

An optical device that is capable of producing plane-polarised light to detect the state of polarisation. A second polarising element is inserted beyond a preparation; when its vibration direction is at right angles to the vibration direction of the polarisation, the field becomes black if no anisotropic specimen is on the stage, or when viewing an anisotropic substance in an extinction position or directly down an optic axis of an anisotropic crystal.