Linear OCT systems

Linear OCT (L–OCT) employs a parallel detection scheme to measure the interference pattern which is formed by the superposition of sample and reference light. L–OCT is one of four basic measurement implementations for OCT. It operates in the time domain like traditional TD–OCT systems but uses a parallel detection scheme by utilizing an image sensor. Therefore, the detection scheme has similarities with FD–OCT. L–OCT shares the lack of the twin–image and autocorrelation artefacts with FD–OCT and the increased noise with time–domain OCT. No moving parts and a simple optical design make L–OCT attractive for optically stable low–cost instruments. One of the main draw–backs is the large number of detector elements, which are needed to achieve a clinically relevant depth range. Gratings offer an elegant solution to reduce the fringe frequency of the interference pattern without influencing the image information. This chapter discusses, theory, implementation and performance of linear OCT systems, together with possible applications and extension, such as non–continuous depth range or line–field versions.