CSIR National Laser Centre develops a high speed OCT system

Abstract

The optical coherence technique (OCT) technique, which was demonstrated by Fercher and Huang in the early 90s, has made significant strides in bio-medical diagnostic applications in the fields of dermatology, dentistry and ophthalmology. Other impact areas and applications include polymer characterisation, surface and thin-film characterisation and biometrics. The National laser Centre has developed a high speed, large area optical coherence tomography (OCT) prototype for fingerprint scanning. The system, which is not limited to this application, can image a large volume (25mm x 25mm x 11mm) and resultant 3-D images (512 x 512 x 2048 pixels) are acquired in less than three seconds. The heart of the system is a swept laser source and a two-axis scanner. Signal acquisition is made possible through a high-speed analogue-to-digital converter capable of speeds greater than 1GS/s. The system has demonstrated the ability to capture live fingerprints making it a viable alternative for high security access control. Furthermore the ability to capture latent fingerprints, from plastic and glass surfaces, was also demonstrated making it applicable to forensics. This paper will present the system design and some of the initial results.