The Theoretical And Experimental Study Of The Superresolving Annular Filters For High Density Storage

The binary or the multiple optical components which are based on thecomputer-aided design and the micro-processing technology have manymerits, such as the high diffraction efficiency, unique chromaticperformance and special optical function. Therefore, these opticalcomponents have been widely used in the data storage, opticalcommunications, the light calculation and other special optical systems.This thesis introduces design theories and producing of two kinds of filtersbased on the genetic algorithm, and their performances are proved bybuilding an experimental system.The design theories, producing and the proved experiments of thefilters are studied in this thesis. First of all, for the binary annular filter, thetransverse and axial gain are defined through the combination of statisticstheory and diffraction theory, based on the definitions about the transverseand axial gain proposed by Sheppard and Hegedus. We choose thetransverse gain as the fitness function and optimize the function by thegenetic algorithm. According to the computation, the correspondingparameters of the filters are obtained. The simulations demonstrate that the filters enable the main lobe of the point spread function to decreasedramatically on transverse, which help to realize the aim of increasingdensity of information storage. On the other hand, the longer depth offocus can also be obtained. The next part is for the multielement annularfilters (binary and quaternary) According to the transverse and axialintensity expressions, an improvable cost function about thesuperresolution and depth of focus is proposed. The correspondingparameters of the filters are obtained by the computation. The simulationsdemonstrate that the multiple annular filters also enable the recording sizeto decrease dramatically. Comparing performance of the binary annularfilters with that of quaternary, the former is better than the latter. Theperformances of binary annular filters designed by the above two methodsare approximate. Secondly, fabrication technologies of the binary annularfilters are studied. The mask graphic of the binary annular filters aredesigned. Then the experimental processing of optical lithography isintroduced. We make certainly the related parameters and produce thecorresponding binary annular filter. At last, the optical system for testingthe performances of the binary annular filters is build. It is shown that thebinary annular filters help to realize the aim of increasing the density ofinformation storage, which is accord to the theoretical computation.