High Energy Pulses from a Wavelength Tunable Dy:ZBLAN Mid-Infrared Fiber Laser

Laser sources in the mid-infrared (MIR 3-5 μm) are increasingly in demand to meet the needs of a variety of applications which exploit the strong ro-vibrational molecular absorption lines in this spectral region. Requirement of high energy pulsed light is found in time-resolved sensing applications such as LIDAR. Fiber lasers in the mid-infrared are promising candidates for generating such pulses, with Q-switched erbium-doped systems demonstrated covering both the 2.8 μm and 3.5 μm bands. However, there remains a sizable `gap' in spectral coverage of such lasers, motivating interest in pursuing alternative rare earth dopants. Dysprosium in particular is a compelling solution, as it possesses a wide gain bandwidth covering 2.8 to 3.4 μm with recent electronically tunable systems closing much of this `gap'.