NASA Langley has been developing the High-Altitude Lidar Observatory (HALO) as a multi-function lidar and testbed to advance the technology needed for airborne and space-based measurements of methane and other gases. These measurements have been identified in the 2018 Earth Science Decadal Survey as a candidate for Explorer class space-based measurements. A laser transmitter capable of generating the online and offline wavelengths needed for the differential absorption lidar (DIAL) measurements of methane is key component of the HALO system.
Fibertek has recently developed the required single-frequency laser transmitter operating in the 1645 nm region for methane measurements. It incorporates the pumping of a seeded optical parametric oscillator with a kHz class single-frequency 1064 nm pump laser. The fielded system can generate 1645 nm seeded output of 2 mJ/pulse at 1 kHz. The laser has been successfully incorporated into the HALO system and used in airborne field measurements. We will discuss the design and performance of this laser and the lessons learned from our development activities.