Diffraction light polariser

A reflection-type light polariser is proposed. It is based on zeroth-order diffraction by a grating consisting of plane elements which include a birefringent medium (two variants). Experimental results obtained at λ = 633 nm for a grating consisting of aluminium stripes deposited on a mica plate agree with numerical calculations that take account of the absorption in the system. The reflectance 0.78 for the selected polarisation and the contrast 50:1 are reported. Special attention is drawn to the suitability of the proposed device for the polarisation of normally incident light (for example, in the fabrication of ‘polarising’ mirrors for laser technologies) and to the feasibility of flexible control of the polariser parameters to suit a specific task.