Research On Techniques Of High-speed Sweep Source Optical Coherence Tomography At 1310nm

Optical coherence tomography(OCT) technology has experienced the development from Time domain optical coherence tomography(TD-OCT) technology to Fourier domain optical coherence tomography(FD-OCT) technology, the parameters of OCT system such as imaging speed, signal to noise ratio(SNR) and resolution has been greatly improved. Swept source optical coherence tomography(SS-OCT) technology is a subtype of FD-OCT, as the latest generation of OCT technology, SS-OCT has the advantages of higher imaging rate and sensitivity compared with Spectral domain optical coherence tomography(SD-OCT), which is another subtype of FD-OCT. SS-OCT is widely used in clinical diagnostics and industrial non-destructive testing field, is becoming a hot topic in recent years. Doppler optical coherence tomography(DOCT) which combines OCT technology with Doppler principle, is a functional extension of OCT and can be used to measure the subcutaneous blood flow. This dissertation focuses on the development of high speed SS-OCT system at 1310 nm and velocity measurement functional extension based on our OCT system, specific research word includes:Research on the principles, development and application of SS-OCT system, design and build the SS-OCT system at 1310 nm, main parts of the system include swept source, interferometer reference arm, sample arm and data collection device. Process data reconstruct two-dimensional slices mages of infra-red card cover glasses and skin samples. The axial resolution can reach 18 μm, A-scan speed of the system is 100 kHz and depth range is above 2 mm.Study on the principles and application of Doppler OCT, functions extended of SS-OCT system and functional extension the OCT system can achieve structure and velocity information at the same time. Vascular blood flow simulation experimental device has been built, which has proved the modified phase-resolved method have better imaging effect than the traditional phase-resolved method, apply the modified algorithm in processing the data of the vessel at different velocity and Doppler angle. A method to improve the minimum detectable velocity has been proposed. Doppler variance method is used to map the flow.We have analyzed noise source of SS-OCT system and proposed a solution to the trigger jitter problem, which can cause interferograms shift at wavenumber space. Cross-correlation method has been used to correct the trigger jitter induced phase instability and get phase stable Doppler OCT image of a mirror.