Spectral Oct Algorithm And System Research

OCT ( Optical Coherence Tomography ) is an noninvasive , high-resolution imaging method .The black and white image gained from OCT can only reflect the intensity difference of scattering light of the sample ,and neglects the spectral information in the range according to the light source. Spectroscopic OCT expands the OCT system function from original imaging to the pick-up and analyses of spectral information.There are two methods to carry out the function expansion from OCT to spectroscopic OCT :The first one is adding prismatic detection component to get spectrum by hardware directly; the second one is not by changing the system's hardware configure ,but by processing the detected interference signal with software module .For the sake of saving system spending ,this paper adopts the second method.We take fast Fourier transform of the interference signal to gain spectral information, and obtain wavelength position of the highest intensity by maximum judgment. The window width of fast Fourier transform is a key parameter related to the balance of space resolution and spectral resolution. We select HLS color space to present both the light intensity and the spectral information, then convert the HLS color space to the RGB color space and display the sample image with 24-bit color map.We prepare standard film for reflectance test and validity check, testify the Fourier transform window width's effect on spectral resolution, calculate the ideal and practical spectral resolution of the system, and choose human finger for in vivo real-time detection.The paper consists of five parts: The first chapter is introduction , which introduces the features, developments and trends of 0 C T,and the significance of this task . The second chapter stretches from OCT theory to spectroscopic OCT theory , and presents the essential theory of spectroscopic OCT. The third chapter is the spectroscopic OCT system actualization .The fourth chapter is experiment results and analyses. Finally there is the summarization and prospect for the wholepaper.