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Why low coherence light in OCT

1.在Optical Coherence Tomography – Technology and Applications的第10页中,提到: Using low-coherence length light, interference only occurs when the path lengths are matched to within the coherence length。 为什么要在OCT系统中使用弱相干光,就是为了获得较小的相干长度,而理论的轴向分辨率是相干长度的2倍。因此,这样就可以得到更小的轴向分辨率。补充一下相关内容: Low-coherence light can be characterized as having statistical phase discontinuities over a distance known as the coherence length, which is inversely proportional to the frequency bandwidth of the light. […]

1.在Optical Coherence Tomography – Technology and Applications的第10页中,提到:

Using low-coherence length light, interference only occurs when the path lengths are matched to within the coherence length

为什么要在OCT系统中使用弱相干光,就是为了获得较小的相干长度,而理论的轴向分辨率是相干长度的2倍。因此,这样就可以得到更小的轴向分辨率。补充一下相关内容:

Low-coherence light can be characterized as having statistical phase discontinuities over a distance known as the coherence length, which is inversely proportional to the frequency bandwidth of the light. When low-coherence light is used, interference is only observed when the measurement and reference path lengths are matched to within the coherence length.

2.在Optical Coherence Tomography – Technology and Applications的第21页中,提到:第一代的OCT系统(1996年)轴向分辨率约为10um,成像速度为100 A-scans/s。到了第三代的Stratus OCT(2002年),轴向分辨率类似,但成像速度提高到了400A-scans/s。

3.在Optical Coherence Tomography – Technology and Applications的第25页中,提到了在内窥成像中,相对于传统组织学分析,OCT成像分析的优势和局限:

OCT imaging relies on intrinsic contrast produced by variations in scattering properties of different tissue structures. On the positive side, OCT enables real time imaging of tissue pathology in situ, without the need for excision and processing as in conventional biopsy and histopathology. When used to guide biopsy, it is not necessary for OCT to perform at the level required for diagnosis, but it must have sufficient sensitivity to detect pathology and improve the sensitivity of excisional biopsy by reducing sampling errors.

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