Semiconductor Lidar for Quantitative Atmospheric Profiling

It is well known that semiconductor lasers offer the important advantages of lower costs, smaller footprint, simplicity, and wider spectral coverage compared to solid-state lasers. However, despite many advances, the output power achievable from semiconductor lasers is still far from solid-state lasers and generally has restricted their use in atmospheric profiling to lidar that does not allow quantitative backscatter information (e.g., ceilometers). Over the past decade, we have been developing lidar architectures using semiconductor sources that provide quantitative observations needed to advance atmospheric science and weather forecasting. This chapter reviews some of the limitations and benefits of this flexible laser technology. We introduce a semiconductor lidar architecture, based on a pulsed overdriven tapered amplifier and traveling wave amplifier, the latter being leveraged as a multifunction switch. This design has been implemented and is being used for the measurement of water vapor, temperature, and calibrated aerosols via DIAL and HSRL techniques. Initial results from an intercomparison with a collocated instrument using our previous baseline architecture will be discussed.