Reducing Inter-Crosstalk in Collinear Holographic Storage System Based on Phase Coding of Reference Light

This paper compares sector and random orthogonal phase coded reference light method (SOPCR & ROPCR) to the cross-talk caused by phase multiplexing by reference light in the collinear holographic storage system (CHSS). The SOPCR divides the ring reference light into eight coding units along the clockwise direction. The ROPCR subdivide the ring reference light randomly divided into eight coding units by pixel. Constructing an 8th-order Walsh-Hadamard phase encoding matrix. Each column in the matrix is recorded as a coding port, and each row in the column is considered as a coding element. The phase spatial light modulator will load the phase information corresponding to the coding matrix onto the reference light coding unit and use these two methods to store the signal light through the channel port, respectively. By comparing the correlation between the read hologram of one channel to other channels, it can be seen that there is evident cross-talk between any two channels of SOPCR, The average Pearson correlation coefficient (CORR) reached 0.57. However, the CORR of the ROPCR is close to 0. ROPCR effectively reduces the phase multiplexing inter-page cross-talk of CHSS and improves the storage density.