Current implementations of OCT can either image over long depth ranges with slower imaging speeds, or at high imaging speeds with more limited depth ranges. The simultaneous operation at multi-centimeter depth ranges and MHz-scale A-line rates is challenging due to limitations in the electronic bandwidths of current digitizers and data transfer buses. The lack of multi-cm depth range, MHz-speed OCT hinders the translation of the imaging technology to sites and organs with complex geometries and expansive fields. Here we describe a first demonstration of a simultaneous cm-scale depth range and MHz-scale A-line rate OCT platform. We describe the principles behind data compression by optically subsampled OCT, the development and performance of a novel subsampled OCT wavelength stepped source operating at 19 MHz A-line rates, the extension of passive quadrature demodulation architectures to GHz-scale acquisition bandwidths, and the first ever integration of these technologies into a subsampled OCT system capable of acquiring volume data at video-rates across multi-cm depth ranges. We use this platform to demonstrate depth resolved measurements over large fields that exhibit complex topography such as the face. The performance, limitations, and the next stages of technical development for this optically subsampled OCT platform are summarized. This platform may open new opportunities for camera-like OCT deployments in sites and organs that are inaccessible to current OCT technologies.
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