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OCT系统里的焦深

1.在Optical Coherence Tomography – Technology and Applications的第27页中,提到: OCT imaging is performed with low numerical aperture focusing in order to have a large depth of field. 通常情况下,成像的焦深大于相干长度,这样就能保证在一定的深度下,系统能够实现相干成像。 2.在Optical Coherence Tomography – Technology and Applications的第29页中,提到: OCM images can be obtained at different depths by adjusting the focus depth while matching the reference arm path delay to the […]

1.在Optical Coherence Tomography – Technology and Applications的第27页中,提到:

OCT imaging is performed with low numerical aperture focusing in order to have a large depth of field.

通常情况下,成像的焦深大于相干长度,这样就能保证在一定的深度下,系统能够实现相干成像。

2.在Optical Coherence Tomography – Technology and Applications的第29页中,提到:

OCM images can be obtained at different depths by adjusting the focus depth while matching the reference arm path delay to the focus depth.

所谓OCM (Optical Coherence Microscopy),就是采用了极高的数值孔径,以至于成像的焦深小于相干长度,以此达到较高的横向分辨率。因此,这种成像方式一般为en face imaging。有一种相关的技术就叫做Full-filed OCT:

Full-field OCT performs high resolution en face imaging with coherence-gated detection using a Linnik interferometer and CCD cameras. Full-field OCT achieves cellular resolution imaging, and because a single spatial mode light is not required, it has the advantage that high axial resolution is possible using low-cost thermal or gas discharge light sources.

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