The superfluorescent single-mode optical fibers source for OCT

Abstract

Optical coherence tomography (OCT) is a new imaging modality that is being actively used in a variety of medical applications. Optical coherence tomography performs cross sectional imaging by measuring the time delay and magnitude of optical echoes at different transverse positions, essentially by the use of a low coherence interferometry to obtain the depth resolved information of a sample. The interference can occur only when the optical path lengths of light in both the sample arm and reference arm are matched to within the coherence length of light source. The most commonly used light sources in the current OCT systems are the superluminescent diodes (SLD). However, the coherence lengths of SLD are typically 10-30 microns that are not sufficient to achieve the resolution required for many medical applications. In the meantime, the moderate irradiance offered by the SLD limits the real time applications for OCT system, which usually require a power with an order of at least 10 milliwatts. Recently the diode-pumped superfluorescent optical fibers sources has been used in a variety of communication and sensor applications. The superfluorescent rare-earth doped optical fibers source is also the very good OCT systematic light source, because of that have a wide bandwidth of fluorescence and high emission power.