Characteristics of Hologram Readout in LiNbO_3∶Fe∶Ru Crystal

The readout characteristics for the hologram recorded in the novel LiNbO_3∶Fe∶Ru crystal have been investigated in order to resolve the problem of hologram data erasure during readout. Grating readout characteristics for two-center and single-center recording are analyzed, and the simulating calculation is performed through jointly solving the two-center material equations and coupled-wave equations. The results show that the readout time constant for a saturated grating recorded by two-center method is much shorter than that in LiNbO_3∶Fe∶Mn; an efficient hologram can be realized with one-color recording, the readout time constant is much larger than the recording time constant, and the quasi-nonvolatile readout can be observed. The analysis shows that Ru perhaps is much easier to be excited than Mn by red light, so the grating persistence would decrease; red light can act as recording light and sensitizing light in one-color scheme, and the grating recorded in Fe can be transferred to Ru, which is weakly sensitizing to red light.