Noninvasive High-axial-resolution Profile Imaging Using Near Infrared Broadband Light Source Based on Self-assembled Quantum Dots

Abstract

This paper reviews development of a near-infrared (NIR) broadband light source based on self-assembled InAs quantum dots (QDs) for optical coherence tomography (OCT) applications. OCT is a noninvasive biological and medical profile imaging technique using low coherent interferometry;thus, its imaging quality primarily depends on light source properties. The InAs QDs, a nanoscale semiconductor material, exhibit a broadband spectrum in the NIR region owing to their size and In composite distributions;hence, they are applicable to high-axial-resolution and large-penetration-depth OCT. We developed a QD-based superluminescent diode (QD-SLD) that emits a spectrum spanning approximately 1-1.3µm with a bandwidth of 144nm. In addition, OCT images of test samples were obtained with the QD-SLD, and the images indicated an axial resolution of ∼4µm, which is a significant improvement compared with conventional SLDs (10-15µm). This practical imaging demonstrates the potential of the QD-SLD as a high-axial-resolution OCT light source.