This SBIR phase II project proposes a single frequency high energy fiber laser system for coherent Lidar systems for remote sensing. Current state-of-art technologies can not provide all features of high energy and efficiency, compactness, narrow linewidth, super frequency and power stability, low noise, and high extinction ratio at the same time. PolarOnyx proposes, for the first time, a high energy (1 mJ) single frequency (< 1 KHz) fiber laser transmitter to meet with the requirement of solicitation. It is a specialty fiber based MOPA operating at 1550 nm. PolarOnyx proposes a revolutionary approach to fundamentally resolve the issues of nonlinear effects by employing our patent pending proprietary technologies in fiber lasers. Our unique spectral shaping techniques enable us to reduce the SBS and ASE noise significantly in the amplifier for commercially available EYDFs and to reuse the residual pump to further increase the efficiency. These will make the fiber laser transmitter system superior in terms of wall plug efficiency (over 30%), energy(1 mJ), noise, size, and cost. In Phase I, we have demonstrated all major functions of the proposed idea and shown a practical energy scaling capability in proof of the concept. A prototype of 1 mJ level fiber laser will be delivered at the end of Phase II.