Experimental research on spatial filtering of deformed laser beam by transmitting volume Bragg grating

Using transmitting volume Bragg gratings (TVBG) as a basis, an experiment on one-dimensional spatial filtering of a deformed laser beam is designed. The deformed laser beam results from a He-Ne laser beam modulated by an amplitude modulation plate with a spatial frequency of 7.2 mm(-1). Results show that when the central wave vector of the deformed beam satisfies the Bragg law of TVBG, the spatial profile of the -1st forward-diffracted order is similar to that of the undeformed He-Ne laser beam due to the TVBG with a spatial frequency selective bandwidth of less than 5.0 mm(-1). The higher frequency components of the deformed beam are filtered out in the optical near field. Thus, the TVBG cleanup of the spatially-deformed laser beam is realized experimentally.