This Phase II program will build and deliver a tunable single-frequency laser operating in the 1.645 micron region on optimum CH4 absorption line features. Under this program an all-solid-state parametric-converted laser will be delivered to NASA LaRC which will be suitable for acquiring range-resolved and column CH4 measurements, and compatible with integration into an airborne methane DIAL system under future programs. Due to its relative insensitivity to aerosol and cloud interferences, a DIAL system based on this pulsed laser source will be ideal for NASA investigating high-latitude CH4 releases over polar ice sheets, permafrost regions, wetlands and over open ocean during night and day. In addition the methane lidar system has commercial applications in detection of fossil fuel leaks. This development advances the laser system TRL from 3 to 5. The proposed laser is designed to be compatible with manned or UAV platforms and traceable to space=based instruments.