Influences Of Key Components And Devices On Performance Of SS-OCT System

Optical coherence tomography(OCT)is a new technique to construct the fine image detection system.Swept source OCT(SS-OCT)system with high imaging speed and signal to noise ratio(SNR)has become the focus of the current promotion application of the technology.To meet the application requirements,it is necessary to improve the performance of SS-OCT system.In this thesis,the influences of key components on the performance of OCT system is studied.In the second chapter,the main performance and technical indexes of the SS-OCT system are discussed,and the influences of the performance parameters of the swept source on the axial resolution,imaging depth and imaging speed of the system are analyzed.At last,the SS-OCT test system with the interfaces of double detections and outputs is proposed and developed,which provides an experimental platform for the research of this thesis.In the third chapter,the influences of swept source on the performance of SS-OCT system are carried out where three swept source modules(SLE-101-1310,SLE-101-1550 and Axsun-SSOCT-1310)are used.The relationship between source wavelength,bandwidth and axial resolution,imaging depth and system SNR is studied.The system SNR versus output power,swept speed,detection depth relations are given under different swept sources with flat,Gaussian and Tukey spectral forms,respectively.The results show the optimum detection performance and imaging quality can be achieved by selecting suitable parameters of swept source.The fourth chapter focus on the wavelength dependences of optical coupler,circulator,polarization controller and their influences on the performance of the SS-OCT system.The wavelength correlation simulation formula for the passive optical devices above are put forward through the experimental testing.And then the digital compensation algorithm integrated the wavelength dependence of three devices is proposed and developed,which is experimentally verified.The results show that the SNR of the system with the integrated digital compensation is improved by 4.15 dB,and the Gaussian output spectrum of the source is more sensitive to the wavelength dependence of the passive optical device.A red/infrared lightwave Mux/DeMux and an integrated optical path in SS-OCT are proposed and designed to explore the ways of reducing the wavelength dependence of the passive optical device and realizing the miniaturization and integration of SS-OCT system.In the fifth chapter,the influences of probe on the performance and application of SS-OCT system are studied.The probe based on single mode fiber for Common-path SS-OCT system is proposed and developed.Based on the endoscopic probe used in the system,the 3D imaging of the inner structure of agate beads is realized.The SS-OCT system based on double probes is set up and the effect of the imaging speed is analyzed by using the dual probes detection.The scheme could improve the imaging speed of the SS-OCT system which validated by the measurement of glass depth.The SS-OCT system for testing Planer Lightwave Circuit(PLC)chips is proposed and built,which tests the parameters of the refractive index,transmission loss,size and structure of the PLC chip.