Diffraction properties study of multi-layer reflection volume holographic grating under ultra-short pulse readout

Based on the modified coupled-wave theory of single volume grating and matrix theory, the time-domain diffraction of multi-layer reflection volume holographic gratings recorded in photorefractive LiNbO3 crystals are theoretically studied when they are illuminated by ultrashort pulse laser. Study shows that the waveforms of the diffracted pulses depend on the readout pulse duration, grating periods, refractive index modulation of the grating, thickness of the buffer layers and gating layers. The diffracted waveforms and intensity can be controlled to satisfy our demands by changing these parameters. Also it is found that the diffracted pulses have a displacement along the time-axis compared with readout pulse. Results of our study can be used in pulse shaping and designing new optical devices based on multiple layers of volume holographic grating.