The Design And Application Research Of Amplitude Liquid Crystal Spatial Light Modulator

With the bases of fully analysis to liquid crystal theory and optical joint transform theory, in this paper, amplitude liquid crystal spatial light modulator is made and it's applied to the joint transform optical fingerprint identification. The main contents include the following aspects:(1) Firstly, strengthen the concept of SLM, then through the analysis of the liquid crystal's electric-optical characteristics and optical properties of the Jones matrix model, the modulation theory of amplitude SLM is got, which provides the basis for the subsequent design and making.(2) With the theoretical basis, select the appropriate LCD screen, in this thesis, Sony's LCX026BLT is selected as a SLM of the LCD screen, and use the Sony driver chip to design hardware circuit. After testing the amplitude LCSLM, we get satisfied results.(3) Before conducting joint transform optical fingerprint recognition, the structure and the principle of the joint transfonn converter is analyzed, then make detailed analysis of the parameters in the joint transform, get ready for subsequent experiments.(4) With the theoretical basis and the analysis parameters and settings of the joint transform, use own amplitude SLM to make joint transform optical fingerprint recognition experiment, respectively select same fingerprint and different fingerprints for the testing, through the analysis of its correlation output spectrum, the same fingerprint correlation's peak is significantly, while different fingerprint results show low correlation peak, in line with prior expectations.There are some shortcomings in this thesis, such as fingerprint recognition on different fingerprints, correlation peak is not particularly ideal, which can be filtered by the direction of the fingerprint, or to improve the experimental method to achieve better results.