The current state-of-the-art 2-µm lidar transmitters for global wind and the CO2 measurement use Ho3+ laser ions respectively doped into LuLiF or YLF host. Ho3+ is typically pumped to a laser transition by a 1.9 µm Tm-based laser which, in-turn, is pumped by semiconductor diodes. This 2-step process compromises electro-optical efficiency and generates significant waste heat while adding volume and weight to the transmitter payload.
Aqwest proposes to develop a novel, efficient, compact, and rugged lidar transmitter based on Tm doped into an innovative ceramic host material. This transformational Tm:ceramic material offers efficient lasing in the vicinity of 2050 nm while being directly pumped by 796-nm diodes, thus resulting in a very simple architecture, more compact packaging, lighter weight, and more efficient operation when compared to the traditional "Tm-pumped Ho" laser transmitters for global wind and the CO2 measurement. The Tm:ceramic transmitter offers high-pulse energy and high-repetition rate in the vicinity of 2050 nm. Aqwest recently demonstrated efficient lasing in ceramic Tm:ceramic with a record continuous wavelength tuning over 230 nm (1890-2120 nm). We are currently developing a kW-class average power 2 µm laser based on the same Tm:ceramic Department of Energy.