Accurate measurement of atmospheric parameters with high resolution needs advanced lasers. In this SBIR program we propose to develop innovative Q-switched high power 2.05micron fiber laser with pulse energy greater than 10mJ, repetition rate of 10Hz to 1KHz, and pulse duration of 200ns using our proprietary innovative highly efficient Tm-doped glass fiber. This new fiber laser will be an all-fiber laser system consisting of actively Q-switched fiber laser oscillator and fiber amplifiers. This proposed all-fiber laser system is compact, highly efficient, robust and highly reliable, which is especially suited for NASA's application where operating environment is always extremely rough. In Phase II we will further optimize Tm-doped glasses and fibers based upon Phase I results, design and engineer 2.05micron Q-switched single frequency fiber laser oscillator, design and engineer 2.05micron fiber amplifiers, integrate Q-switched single frequency fiber laser oscillator and fiber amplifier, build and deliver a prototype high power Q-switched single frequency 2.05micron fiber laser.