Information Stored Three-dimensional Diffraction Theory Analysis And Computer Simulation

Traditional optical disc recording technology has limited storage density and low information transfer rate due to laser diffraction spot size limitation (micron order of magnitude). A new type of 3-D storage technology is proposed in thesis.With following features:It has 3-layer information storage media, with large capacity.Three wavelengths can be simultaneously transferred in parallel with preserving polarization fiber. As a result, average access time can be decreased, and data written and read storage rate can be increased.Three tasks are completely researched in this thesis:A new 3-D storage system has been designed and its individual unit is expanded on and analyzed. Its originality is: taking three kinds wavelengths (530nm, 650nm, 780nm) of semi-conductor laser array as light source; A detector array which can detect these three wavelengths is used; Three wavelengths are simultaneously transferred in parallel with preserving polarization fiber; Parameters of focusing object lens and structure of 3-D storage media are designed.Based on diffraction theory, the 3-D storage system is analyzed. It includes introduction of Canonical Coordinates. Simple periodical arrangement of concave pits, the effects of the obliquity of collimated beam to optical axis, and the mutual modulation and cross-talkBased on theoretical analysis, simulation is conducted and factors which affecting light intensity distribution are analyzed. The storage system mentioned in the thesis can realize to read and write of 3-layer information media, so the storage capacity and data transfer rate can be effectively increased respectively. This idea of thinking can be served as inspiration to further enhancing storage capacity and increase the access rate, and it can be advanced the information storage of way. The simulation results in chapter 4 indicated that: Light intensity distribution of concave pit meets Strehl Standard. The system can perform 3-D reading and writing simultaneously. It proves that this theory analyses are practicable.