Abstract: A high density rapid access data storage device employs a volume of field-oriented bacteriorhodopsin in a polymer medium, and contained in a vessel that can be accurately displace in three dimensions. X-axis and Y-axis laser illumination systems each converge a beam in the respective direction at a location at which a particular bit cell is to have a "1" or "0" recorded or is to be interrogated. Both laser systems are pulsed on at one wavelength to write a "1" or at a second wavelength to write a "0". After writing, a cleaning step is carried out by actuating the laser systems non-simultaneously at the other of the wavelengths to remove any undesired photochemistry from adjacent bit cells. A read cycle involves actuating two or four lasers, and then discriminating the "1" or "0" state from the electrical signal generated by the medium.