13.4 MHz FDML Laser for Intra-Surgical Optical Coherence Tomography

Abstract

Fourier domain mode locked (FDML) lasers are rapidly swept laser sources which are predominantly used for optical coherence tomography (OCT), a non-invasive depth resolving imaging modality [1]. State of the art FDML lasers achieve sweep repetition rates up to 5.2 MHz enabling MHz-OCT with video update rates and meter long coherence lengths allowing for working distances of several centimeters [2, 3]. Recently, researchers are pursuing the goal to implement MHz-OCT into surgical microscopes assisting the surgeon to get intra-operative guidance and identification of tumor infiltration [4]. During surgery, high resolution OCT-volumes (>1024×1024 A-Scans) with video update rates (>24 fps) are required which is a speed beyond the standard MHz-OCT capabilities. These prerequisites demand A-Scan rates exceeding 10 MHz. To meet these requirements, we present an FDML laser with 13.4 MHz sweep repetition rate sweeping over 113 nm centered at 1300 nm.