Diffraction properties of ultrashort pulsed beams generated from local volume holographic gratings with arbitrary boundaries

On the basis of two-dimensional coupled-wave theory, diffraction properties of ultrashort pulsed beams (UPBs) generated from volume holographic gratings with arbitrary boundaries are studied. The resulting differential coupled equations are solved numerically by a two-dimensional Runge-Kutta method. The effects of the grating boundaries on the intensity distributions of the diffracted and transmitted pulsed beams in spectral and temporal domains are presented, and the effects on the Bragg selectivity bandwidth, the diffracted bandwidth and the total diffraction efficiency of the gratings are also given. Simulation results show that use of a characteristic grating will result in distorted profiles for the diffracted beam and that truncated grating shapes significantly improve the output beam quality. This study presents the possibility of shaping a broadband UPB by controlling the boundaries of local volume hologram gratings.