Measurements of wavelength of light sources by ellipsometry technique

In the present paper, we propose a simple ellipsometric technique for measuring the wavelength of monochromatic radiation up to 10-3 nm. The method is based on measuring the phase shift between two orthogonal components of the electric vector in the light transmitted by an anisotropic plane-parallel plate versus wavelength. The technique was used to measure the temperature-induced shift of the emission spectrum of a light-emitting diode. The data obtained were verified by comparing them with spectrophotometric. The method can be easily implemented on commercially available ellipsometers and mini-ellipsometers.