Amplitude gratings generation by selective defect bleaching in KCl:CO_3K_2 crystals

Abstract

Volume grating formation by spatially-selective defect bleaching is demonstrated in coloured KCl:CO_3K_2 crystals. The sample is coloured by a train of pulses with a wavelength of λ= 266 nm and bleached with a cw Ar-laser with a wavelength of λ= 514.5 nm. Diffraction efficiency for a 1.6 μm grating period is studied both experimentally and theoretically, using the evolution of colour centre concentration. Hologram recording parameters are obtained and the evolution of the spatial grating profile is discussed. Diffraction efficiencies three times higher than previously published efficiencies are obtained.