Single-shot full-field OCT based on four quadrature phase-stepped interferometer

摘要

We demonstrate a compact single-shot full-field optical coherence tomography (OCT) system for obtaining real-time high-resolution depth resolved en-face OCT images from weakly scattering specimens. The experimental setup is based on a Linnik type polarization Michelson interferometer and a four-channel compact polarization phase stepper optics. The four-channel phase-stepper optics comprise of a dual channel beam splitter, a Wollaston prism and a pair of wave plate for simultaneously capturing four quadratually phase-stepped images on a single CCD. The interferometer is illuminated using a SLD source with a central wavelength of 842 nm and a bandwidth of 16.2 nm, yielding an axial resolution of 19.8 (am. Using a 10 × (0.25-NA) microscope objective and a CCD camera with 400 × 400 pixels, the system covers an area of 225 μm × 225 μm with a transverse resolution of 4.4 μm. The en-face OCT images of an onion is measured with an exposure time of 7ms and a frame rate of 28 fps.