Batch recording of multiple SQAM signal and self-reference detection technique.

The development of holographic data storage is expected as a next-generation large-capacity memory. The recording scheme of spatial quadrature amplitude modulated (SQAM) signal, whose amplitude and phase are individually modulated with multi-levels, is a promising technique to improve the recording density of the memory. In this paper, we propose a method to simultaneously record multiple SQAM signals with different angles in the holographic memory. We also propose a method to detect the amplitude and phase value of the SQAM signal from the interference intensity distribution formed by the two SQAM signals selectively reproduced from the memory. We evaluate the decoding accuracy when the multiple SQAM signals generated by the interleaved phase method are recorded and the two signals are extracted and readout numerically. We also give experimental result as proof of principle of the decoding process. In the end, we analyze the accuracy against multiple number of SQAM signals on a recording page. [ABSTRACT FROM AUTHOR]