Retinal Spectral Domain Oct Imaging Technology Experimental Study

As a novel non-destructive testing technique, optical coherence tomography (OCT) has played important role in the modern eye clinical due to the detailed advantages including high resolution,real time and non-contact measurement.The principle and characteristics of optical coherence tomography (OCT) is discussed in this paper. We set up optical coherence tomography system with near-infrared broadband Gaussian light source, and discuss about the detailed methods for invisible light path adjustment. Combined with eye's features, a series of performance evaluation parameters are determined for optical coherence tomography system, and the corresponding requirements for each optical element are designed based OCT system performance. Then nonlinear effect of spectrum distribution is calibrated by light wedge located between diffraction grating and detector.Based on the simulation model in ZEMAX,the algorithm of depth information extraction is discussed for spectral domain OCT system with multi-layer sample. After setting up spectral domain OCT, glass slide and onion skin tissue is replaced as single-layer and multi-layer sample in order to verify the reference mirror move method, respectively. Then the influence on diffraction stripes is discussed according to the result when optical path difference (OPD) between reference arm and sample arm changes. The thickness and internal layer depth information of onion skin is obtained after noise reduction. Besides, we also describeπphase shifting method with PZT used to noise reduction, and discussπphase calibration method.The result shows that reference mirror move method can eliminate the auto-correlation and cross-correlation noise in onion sample and it is easily to extract the detailed layer information which conforms to the onion sample structure.