Design Of OCT-based Finger Biometric Acquisition Front-end Device

With the development of information technology,personal identification has been widely used in the field of national security and consumption.,biometrics based on fingers occupy 58%of the market at present,but the traditional finger biological features are faced with two bottlenecks:single mode and weak anti-counterfeiting ability.The dermal fingerprints,sweat pores,sweat glands and other biological characteristic is unique and strong security.However,it is difficult to use the traditional acquisition method for the above modal information,the corresponding device is lack,and the image quality is poor.After analyzing the basic research of optical coherence tomography(OCT)and finger biometrics acquisition,this thesis proposed and designed the finger biometrics acquisition device based on OCT which is aimed at the shortcomings of the single-mode of traditional finger biometrics acquisition.The main work and achievements of the thesis are summarized as follows:(1)The hardware design of linear CCD(Charge Coupled Device)camera circuit based on OCT:After analyzing the requirement of hardware system,the characteristics of high resolution and high speed in biometric acquisition application,independently design high-speed and high-resolution linear CCD camera hardware prototypes,wich includes the core processing module and CCD control module.(2)Design of frequency domain OCT optical system based on finger tissue imaging:after analysis of traditional interferometry methods,the overall optical structure of OCT based on fiber Michelson interferometer is designed,which includes broadband light source,imaging interferometer,sample scanning system and spectrometer,etc,each module transmits optical signal through optical fiber.In order to optimize the imaging performance of the system,the optical evaluation parameters of each module are theoretically analyzed,and the actual verification is carried out.Finally,the OCT Interference spectrum output is completed by using this optical system.(3)Acquisition device system debugging and experiment:According to the previously self-designed linear CCD camera and frequency domain OCT optical system,build a acquisition platform for debugging and experiment.Firstly,the debugging of CCD camera driver and synchronous acquisition are completed.Finally,the image acquisition experiment of the finger.