Research On Extending The Effective Ranging Depth And Improving The Lateral Resolution Of Spectral Domain Optical Coherence Tomography System And Method

Optical coherence tomography is a new kind of biomedical optical imaging technology,which has the advantages of high sensitivity,non invasion,no radiation and so on.It has broad application prospects in the field of biomedical and other fields.With the development of science and technology the SDOCT as the second generation OCT has great imaging speed and sensitivity.The three dimensional(3D)OCT images can be acquired by using the SDOCT system.Firstly,the basic principle of SDOCT technology is introduced.The system design and implementation process,the synchronization acquisition of the scanning drive signal and data acquisition signal are also introduced in detail.Then the en face images from different depth that are acquired using the 3D SDOCT system are shown.The important performance parameters of the SDOCT imaging system are discussed.Secondly,the spatial frequency domain multiplexing method is proposed for extending the imaging depth of SDOCT system.The method can realize simultaneous imaging of samples with different depth regions without any expensive acousto-optic or electro-optic modulation device.The working principle of the method is described in detail and the sensitivity of the system is tested.Compared with the traditional full range SDOCT,the samples images reconstructed with the proposed method demonstrate the expected increase in the effective imaging depth range.Thirdly,the methods of solving the contradiction between the lateral resolution and the focusing depth of the OCT system are presented.This paper introduces a kind of digital refocusing method that based on the 3D SDOCT system,and the experimental scheme is designed.Finally,I research a problem that the measurement of the cell sample displacement has phase wrapping by using spectral domain phase microscopy.Then the solutions that are proposed by the research groups are analysed.A new unwrapped method which combines the spatial domain and spectral domain is proposed.The design and implementation process of the SDPM system is introduced in detail.The sensitivity curve of the system is shown.The acquired unwrapped SDPM image demonstrates the effectiveness of the method.