Atmospheric methane is the second most important anthropogenic greenhouse gas. The overtone lines of methane at 1.65 micron are well suited for remote sensing of atmospheric methane in the Earth's atmosphere. NASA have already demonstrated ground-based and airborne methane detection using Optical Parametric Amplifiers at 1651 nm using a laser with a narrow linewidth. In this setup a single frequency pulsed laser near 1 micron wavelength with several mJ pulse energy is needed. We propose to develop a compact pulsed single frequency fiber laser with greater than 3mJ pulse energy and 30ns pulse width using our innovative Yb-doping fiber. Highly efficient Yb doped glasses will be developed, double cladding fibers will be designed and fabricated, the amplifier performance will be characterized. In Phase II we will build a deliverable prototype high energy and high peak power fiber laser system for NASA.