Polarisationsdatenspeicherung in Bakteriorhodopsin-Schichten

The distribution of knowledge, rules and laws in the form of stored information has begun with simple stone tablets and papyrus rolls. It developed printed media and nowadays the use of computers for data storage is common. Magnetic hard drives can store a few terabits. The optical information storage with CDs (compact discs) and DVDs (digital versatile discs) is widespread. However the number of pits and flats is limited and a regular CD can only store up to 700 MB. By decreasing the laser spot size and using other wavelengths the capacity volume for storage expands up to 50 GB in a blue ray disc. But still the limits of data storage are not yet exhausted. The optical data storage can be extended into five dimensions, including the spatial resolution in XYZ-direction of the storage medium and the readout wavelength for different dyes. Furthermore the polarization state of light provides an additional degree of freedom to increase capacity. Optical polarization data storage is also possible with Bakteriorhodpsin (BR). Research on BR has been done since its discovery in the 1970s. In recent years more and more possibilities for technical applications of this biomolecule have been discussed. BR has an enormous stability against thermal and chemical stress, therefore it is ideal for technical applications. The combination of existing techniques with BR is an important requirement for the market introduction of products containing BR. These products include for example photochromic security inks using molecular effects of BR, inspired by the proton pump mechanism of this protein in nature. BR also has a huge potential in the application as optical polarization-encrypted data storage. Therefore, the already known technique of data storage in BR has to be investigated with regard to the writing and reading mechanism. Moreover, the molecular effect, which leads to a macroscopic measurable polarisation change of incident light has to be devised. A combination of UV-Vis-spectroscopy, CD-spectroscopy and atomic force microscopy of laser irradiated samples was able to show the structural changes on the molecular level. Together with MS-analyses the irreversible reaction of laser induced two photon photo-bleaching has been solved in this work. In this PhD thesis techniques and procedures were combined to produce polarization data storage containing BR. The effect of polarisation storage was analyzed and described employing the Stokes formula. The capacity of data storage increases enormously by using a polarisation system.