Research On Full-field Optical Coherence Tomography System Based On InGaAs Detecto

Full Field Optical Coherence Tomography(FFOCT)technology is capable to extract highresolution images for the inner structure of samples in a non-invasive manner,which can be used to facilitate other research fields such as disease diagnosis and material analysis.Nevertheless,the detectors in most of the FFOCT systems can only detect visible lights,which limits the areas where the FFOCT can be applied for.In this paper,aiming to explore the FFOCT system working in other spectral bands,we focus on the design of FFOCT system with Indium Gallium Arsenide(In Ga As)detectors.Firstly,we briefly introduce the overview of OCT system and In Ga As detector as well as their corresponding development.Then,we explain the design of FFOCT system with the In Ga As detector,including the illumination light system,reference arm,sample arm,and detection arm.The system has the In Ga As-based focal plane as a detector to capture interference light with wavelength ranging from 900 to 1700 nm.Next,based on Python,we build a software integrating the demodulation algorithm for interference images and the denoising algorithm for demodulated images.In particular,for each image,the de-noising algorithm is designed to adaptively suppress the speckle noise in the FFOCT system and the noises caused by non-uniform response in the In Ga As detector.We derive the iterative denoising algorithm from Plug-and-Play Alternating Direction Method of Multipliers(P&P ADMM)and adopts an off-the-shelf deep convolutional neural network.Through measuring on the interference fringes of equal thickness,the system axial resolution is 2.0 μm.yy comparing with the 1951 USAF standard resolution board,the system lateral resolution reaches4.38μm.Furthermore,we conduct experiments on the onion epidermal cell and image the cells structures from the surface to the position 20μm below.Finally,the developed FFOCT system with In Ga As detector is extended to detect interference signals of short-wave infrared light,serving as a potential solution for the development of FFOCT system with deeper imaging depth.