Quasi-telecentric optical design of a microscope-compatible OCT scanner.

We report an optical coherence tomography (OCT) scanner design with optimized quasi-telecentric optics. This scanner achieves a uniform, Gaussian spot size of 15microm (1/e(2) diameter) over a range of 4.4mm in two orthogonal transverse scan dimensions. Model simulation using optical design software agrees with measurements by beam analyzer. We provide a reasonable design criterion of 0.05 (the ratio of the half separation of two orthogonal scanning mirrors to the front focal length of the optics that follow) for the quasi-telecentric scanner which corresponds to a spotsize and spot ellipticity variation of only 4% over the transverse scan range. Furthermore, this OCT scanner accommodates a microscope to precisely guide and document OCT imaging of small samples. OCT images of in-vivo human skin, human nail fold, and embryonic hearts (avian stage 22 and stage 28) demonstrate the image quality achieved with the scanner. The results indicate that optimizing the sample scanner optical design is important for optimizing OCT image quality.