Quantum-Cascade-Laser-Seeded OPO for DIAL

We propose to develop an all-solid-state, laser-based source that covers the 2.5- to 14-micron band and is suitable for use in airborne and space-based differential absorption lidar (DIAL) systems. The proposed DIAL transmitter would enable high-resolution, high-accuracy remote sensing of atmospheric molecular species of interest to NASA including carbon monoxide, carbon dioxide, methane and nitrous oxide as well as many others. The proposed project would yield a deliverable laboratory-level system comprised of a diode-laser-pumped, Q-switched, 2-micron laser, which pumps a middle-wave-infrared (MWIR) optical parametric oscillator (OPO), that is injection-seeded with a quantum cascade laser (QCL) to provide a narrow linewidth. The primary innovation is the use of recently developed distributed feedback (DFB) QCLs to injection-seed a MWIR OPO for the purpose of obtaining narrow linewidth, high-pulse-energy operation in a compact, simple configuration. A secondary innovation is the specific selection of other critical system components that make the overall system suitable for airborne and space-based instrumentation. These include the all-solid-state 2-micron pump laser and the MWIR OPO, which can be constructed with either zinc germanium phosphide (ZGP) or cadmium selenide (CdSe) depending on the wavelength coverage desired.