INFRARED-RAY POLARIZATION CONVERSION PROCESS Russian patent published in 1997 - IPC

FIELD: laser engineering. SUBSTANCE: polarization conversion is effected during diffraction of incident rays under Wood anomaly conditions (resonant excitation of surface electromagnetic waves on diffraction gratings with profile depth h<λ,d and period d≥λ; phase shift may be in the range n<Φ<n. For example, linearly polarized rays with wavelength λ = 10,6 can be converted into circular-polarized radiation with conversion efficiency η ≃ 92-96%. In addition, adequate choice of grating parameters enables stable phase shift and effective conversion while wavelength and angle of ray incidence on grating are varied within wide range. EFFECT: improved conversion efficiency. 2 cl, 2 dwg, 1 tbl