Description: For NASA's various types of coherent LIDAR applications, NP Photonics propose to develop a 50 mJ monolithic 2 micron pulsed fiber laser transmitter in 200 ns regime with transform-limited linewidth, leveraging on NP's proprietary germanate active fibers. NP's patented large core SM PM highly Tm-doped germanate glass fibers have high unit gain and high stimulated Brillouin scattering (SBS)-threshold. We will use our proprietary single-frequency actively Q-switched fiber laser seed in order to make the whole high power narrow linewidth pulsed fiber laser transmitter compact and expandable to spaceborne or UAV platforms. In Phase I, one new SM PM highly Tm-doped germanate fiber with 25 micron core will be fabricated and used for the power amplifier stage in order to demonstrate 1-5 mJ pulse energy and ~ 10 kW peak power for 200 ns fiber laser pulses with SBS-free. In Phase II, 100 micron core germanate fiber will be designed and fabricated in order to demonstrate 50 mJ fiber laser pulses with 100's kW SBS-threshold and transform-limited linewidth. In this project, NP Photonics will offer prototype/product service to NASA by delivering 1-50 mJ monolithic 2 micron pulsed fiber laser transmitter in 200 ns regime with transform-limited linewidth.

Benefits: The proposed 50 mJ monolithic 2 micron pulsed fiber laser transmitter in 200 ns regime with transform-limited linewidth can be used for high resolution laser spectroscopy, velocimetry, anemometry, coherent Lidar, imagery, laser frequency conversion, and ranging finding owing to their high spatial and spectral qualities. The related high SBS-threshold fiber amplifier based on NP's germanate fibers can be used for narrow linewidth CW and pulse amplification in nanosecond/microsecond regime due to the high SBS-threshold threshold. The related 50 mJ fiber laser pulses can be used as pump for parametric Mid-IR generation.

NASA's Langley Research Center, Goddard Space Flight Center, and Ames Research Center have been investigating a number of remote sensing concepts using 2 micron lasers. For example, they are developing a 2 micron pulsed coherent Differential Absorption LIDAR (DIAL) for range resolved atmospheric CO2 measurements The proposed 50 mJ monolithic 2 micron pulsed fiber laser transmitter in 200 ns regime with transform-limited linewidth is ideal source for NASA's fiber laser coherent LIDAR and spectroscopic instruments from ground, airborne, and space-based platform. Also, it can be used in other planned missions or technology programs, such as Doppler Wind Lidar, Lidar for Surface Topagraphy (LIST), and Earth and Planetary Atmospheric Composition (ASCENDS).