Estimation of insertion loss of a holographic switch with an optically addressed spatial light modulator

We investigate the cause of the insertion loss of our holographic switch by determining the relation between the diffraction efficiency and the hologram patterns generated by the control beams. According to the calculation the theoretical insertion loss is 7.4 dB with loss distribution of 0.03 dB under the conditions of a previous experiment. We find that incomplete storage of the interference pattern on the optically addressed spatial light modulator is the strongest factor determining the insertion loss.