Three kinds of OCT, time domain, frequency domain and functional, were discussed, the imaging theory of each was introduced and their endoscopic version were described.

• 分时域、频域和功能OCT三部分进行讨论，简述每种OCT的成像原理，分析它们各自的特点，提出每一类OCT技术与内窥镜结合的结构简图。