Parallel Optical Data Storage Using Genetic Mutant Bacteriorhodopsin Photochromic Films

Baoli Yao1, Ming Lei1, Yingli Wang1, Yuan Zheng1, Neimule Menke1, Guofu Chen1, and Norbert Hampp2

1State Key Laboratory of Transient Optics Technology, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710068, P. R. China, and
2Institute of Physical Chemistry, Philipps-University, Hans-Meerwein-Str., D-35032 Marburg, Germany




Bacteriorhodopsin (BR) is a photochromic retinal protein existing in the purple membrane of Halobacterium Salinarum. It is regarded as a promising nanobionic material having greatly technical applications in holographic recording, optical memory and optical information processing due to its effective photochemistry, high stability and unique reversibility compared to other photochromic compounds. But the wild type BR has some disadvantages in optical applications. For example in many applications a longer metastate is needed, but the longest lifetime of the M state is only in milliseconds. P (Q) state is found to be stable at room temperature, but the efficiency from B to P state is very low in wild type BR (~0.02%). Genetic engineering provides a powerful tool to modify the properties of the molecule to satisfy the requirement. Here we present the application of genetic mutant BR-D96N and BR-D96N/D85N fims as recording media in parallel optical data storage. For BR-D96N, which is M-type photochromism, the information storage period is about 10min. For BR-D96N/D85N, which is P-type photochromism, the information is permanently stored. The parallel optical method can largely increase the speed of data writing and reading in comparison with the bit-type recording. The system is composed of a LC-SLM as a data array input component, a CCD camera as a readout device and a micropositioning stages as an addressing equipment. Micro-images and binary digital data are recorded, readout and erased in this parallel system. At present time the data storage density is 3×107 bit/cm2.