%0 Journal Article
%T Full-Field and Single-Shot Full-Field Optical Coherence Tomography: A Novel Technique for Biomedical Imaging Applications
%A Hrebesh Molly Subhash
%J Advances in Optical Technologies
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/435408
%X Since its introduction, optical coherence tomography (OCT) technology has advanced dramatically in various field of both clinical and fundamental research. Full-field and Single-shot full-field OCT (FF-OCT and SS-FF-OCT) are alternative OCT concepts, which aims to improve the image acquisition speed and to simplify the optical setup of conventional point-scan OCT by realizing direct line field or full-field sample imaging onto an array or line detector such as CCD or CMOS camera. FF-OCT and SS-FF-OCT are based on bulk optics Linnik-type Michelson interferometer with relatively high numerical aperture (NA) microscopic objectives. This paper will give you an overview of the principle of various types of FF-OCT and SS-FF-OCT techniques and its associated system design concept and image reconstruction algorithms. 1. Introduction Optical coherence tomography (OCT) is a novel noninvasive optical imaging modality based on low-coherence interferometry. The first version of this technique was devised in 1990 by Dr. Naohiro Tanno, a professor at Yamagata University [1, 2], and then perfected in 1991 by Massachusetts Institute of Technology team headed by Professor James Fujimoto [3]. OCT can enable the noninvasive, noncontact imaging of cross-sectional structures in biological tissues and materials with high resolution. In principle, OCT is an optical analogue to clinical ultrasound. In OCT, the temporally gated back-reflected optical pulse remitted from scattering sites within the sample is localized by low-coherence interferometry (LCI) [4¨C8]. This is typically achieved with a Michelson interferometer. The sample rests in one arm of the interferometer, and a scanning reference optical delay line comprises the other arm. In LCI, light interferes at the detector only when light reflected from the sample is matched in pathlength to light reflected from the scanning reference mirror. A single scan of the reference mirror thus provides a one-dimensional reflectivity profile of the sample. Two-dimensional cross-sectional images are formed by laterally scanning the incident probe beam across the sample. The reconstructed OCT images are essentially a map of the changes in the refractive index of refraction that occurs at internal interfaces. Just like ultrasound images, the discontinuities in acoustic impedance occur. The principle difference between ultrasound and optical imaging is that the velocity of light is approximately a million times faster than the velocity of sound. For this reason, the distance within the materials or tissues with a resolution of 10£¿¦Ìm by
%U http://www.hindawi.com/journals/aot/2012/435408/