A high speed OCT system developed at the CSIR National Laser Centre (paper)

Abstract

Light-based techniques continue to gain momentum in different spheres of diagnostic and therapeutic applications due to their non-invasive, non-contact properties. One such technique is Optical Coherence tomography (OCT). Since first being reported by Huang in 1991, OCT has made significant strides in different fields such as dermatology, ophthalmology, polymer characterisation and biometrics. The type of OCT system employed can be a simple, cost effective solution or a complex, highly specific and fast system depending on the application. As part of a larger project, we have designed and built a high speed OCT system that can image a large surface area (25 by 25 mm) to a depth of 11 mm (sample dependant). Resultant 3-D images (512 x 512 x 2048 pixels) are acquired in less than 3 seconds. The heart of the system is a 200 kHz swept laser source and two-axis galvanometer based scanner. Signal acquisition is made possible through a high-speed analogue-to-digital converter capable of speeds greater than 1GS/s. This paper will give an overview of the system design and the specifications that have been obtained.