Non-interferometric phase retrieval for phase-modulated holographic data storage (Conference Presentation)

A non-interferometric phase retrieval method in the phase-modulated holographic data storage system is proposed. This method can not only avoid phase ambiguity issue with interferometric, but also increase the capacity by reducing media consumption. Iterative Fourier transform (IFT) algorithm is one of easiest non-interferometry methods. We choose to use IFT algorithm due to its compact and stable realized system and simple single-shot operation. Strong constraint conditions such as phase-only and embedded data which are known phase values of the certain positions on the encoded data page are provided to realize accurate and quick phase retrieval in the holographic data storage system. We demonstrated the phase retrieval process of the recorded 4-level phase pattern in the media experimentally. Besides, we can realize one-time Nyquist frequency recording which is the limitation of recording area by using the non-interferometric phase retrieval method and the periodicity of Fourier frequency spectrum. Therefore, the media consumption can be reduced by 35%. Eventually, we can increase storage capacity by at least 1.5 times.