This SBIR Phase I effort will demonstrate the feasibility of developing a tunable, high-power, narrowband seed laser source integrated with a broadband, waveguide-based second harmonic generation (SHG) module to allow in situ alignment, component testing and calibration across the tuning range of fiber-based lidar systems for measuring atmospheric oxygen concentrations. The lidar is being developed as part of a dual-wavelength remote sensing system for high precision CO2 measurements. Active laser-based spectroscopic remote sensing can map changes in CO2 concentration over the entire globe. However, the measurement of CO2 concentration varies depending on properties such as humidity, temperature, and pressure. To remove these variables, measurement of a stable, well-mixed gas such as oxygen is required as well. Generation of a broadly tunable SHG source with integrated laser for downstream seeding will further this approach.