Optical Spatial Mode Converter For Algorithm Research And Software Design

For the wave band, people need to transform one mode to another according to different practical needs. However it is an efficient method to solve this problem with computer optical element. The recent articles show that the computer optical element could realize the transforming of the mode in light wave, microwave and millimeter wave band. In this paper, we design an optical space mode converter which is used in light wave band, And it realize a specific mode transformation from the ideology of computer optical element. It's mainly composed of the theoretical analysis of elements, software design and verification of relevant experiments. Firstly, the paper gives a detailed analysis of the design of computer optical element. It researches scalar quantity diffractive theory and several large-scale optimal algorithms mainly. And a comparison of the advantages and disadvantages of GS(Gerchberg-Saxton)algorithm, Yang-Gu algorithms, Genetic Algorithms(GA) and Simulated Annealing Algorithm is given. With this foundation, it uses GA algorithm to improve the traditional GS algorithm and proposes an algorithm of the mode converter design based on the combination of GA and GS algorithm. With the basis of this algorithm, the paper uses an object-oriented design method and develops a kind of simulation software of optical space mode converter based on C++. This software can easily realize the simulation design of the element of each image which is given. It also solves the problems of traditional Matlab simulation software, such as slow speed, the poor of program iteration, unfriendly user-interface, etc. In the process of software design, it gives an overall analysis by using the unified modeling language (UML). So it has a figure of reusing. This article analyzes and designs the computer optical elements which can shape the laser beam to a letter shape,special shape and several aimed pattern shapes. This simulation results and expected results are matching. This paper shows an analysis of the simulation results from above design theories and draws a conclusion with a reference value in some extent. All these give us an instructive meaning for the design of computer optical elements in the future. In the end, this paper has the experiment verification and obtains an expected result. It validates the correctness of the design method and software programming further.