A numerical method is developed to investigate the properties of polarization diffraction gratings. The diffraction efficiency and polarization state of the diffraction orders are investigated in 3 main cases - when recording with two circularly polarized waves; when recording with two linear polarizations and in the general case - two orthogonal elliptical polarizations. The linear and circular anisotropy of the recording media are taken into consideration. The result in particular cases known from the practice or where analytical expressions have been reported, are in agreement with the model predictions.
We propose here a device for measuring the ellipticity of light. Its core element is a polarization diffraction grating. As far as we know, no other similar device has been developed so far. To record the grating holographically we used a Mordant Pure Yellow azodye in a matrix of gelatin. This media acquires relatively high values of birefringence (over (Delta) n = 0.02) which can be stable for more than a year and no surface relief appears during the recording Thanks to these advantages we succeeded to record polarization diffraction gratings that can be used as circular analyzers. Diffraction efficiency of 67% is achieved at 633nm. Based on that polarization grating, a novel type of a compact ellipsometric device working with white light was built. The different wavelengths are spatially separated and measured by means of a CCD line. The device has no moving parts and permits measuring of the ellipticity at different wavelengths simultaneously in real time at a high speed (only electronics limited). Initial experiments with the device were done.
Mordant Pure Yellow azodye in a matrix of gelatin is proposed as a media for stable polarization recording. Relatively high values of birefringence are measured (over (Delta) nequals0.02). Polarization diffraction gratings are recorded with two circularly polarized waves and diffraction efficiency of 67% is achieved at 633 nm. Protected from the humidity, the recording is stable. Long term radiation by 633 nm probe beam is harmless as well. Unusual behavior is observed when acting on the recorded grating alternatively with one of the recording beams. The left circularly polarized beam erases the grating sharply, while the right circularly polarized beam, before erasure, first increases the diffraction efficiency.