Light-induced Discoloration Characteristics Of Prototype Devices Based On Bacterial Rhodopsin

Bacteriorhodopsin is the unique protein in the purple membrane of Halobacterium. Upon the absorption of light, BR undergoes a complex photocycle characterized by different intermediate states spectroscopically distincted and can return to the ground state. Genetic engineering and chemical technology are very powerful for the controlled modifications of the physical properties of BR according to the demands of technical applications.M state of variant D96N and P state of variant M1B show stable thermal prosperity at room temperature and we can implement several simple logical gates upon D96N film based on the nonlinear relationship between population distribution on M state and exciting light intensity. Study on the optical storage prosperity of D96N, permanent information storage character of M1B, and optical switches and inverter controlled by light are demonstrated, using the different absorption of ground state and excited state. Near field scanning optical microscopy is a powerful tool to realize super high-density information storage. Our experiment with NSOM gives the proof that BR shows its remarkable photochromic character in the near field of BR film as well as in the far field, which confirms us that BR can be used as optical media for super high density information storage and micro devices of optical information processing.