Sodium Excitation Laser for Mesospheric Analysis

The sodium layer in the upper atmosphere provides a unique opportunity to study mesospheric and ionospheric dynamics, as its density, temperature, and altitude fluctuate due to various atmospheric and geophysical factors. These variations can be probed through remote sensing, with sodium serving as a natural tracer. Despite its significance, the mesosphere and lower thermosphere (MLT) region remain poorly characterized, even though they are critical for understanding atmospheric dynamics. Pulsed lasers with high peak power have traditionally been the primary light source for probing the sodium layer via LIDAR detection. However, achieving remote detection at a 90 km range typically requires bulky, power-intensive laser systems, limiting their use to ground-based applications. To enable space-borne and/or balloon-borne LIDAR operations, Opto-Atomics Corp. (OAC) proposes the development of the Sodium Excitation Laser for Mesospheric Analysis (SELMA)—a compact, continuous-wave (CW) 589.16 nm laser transmitter designed for remote sodium detection in the upper atmosphere. SELMA’s primary objective is to facilitate field deployment of sodium LIDAR for characterizing the mesospheric sodium layer, enabling remote sensing of temperature, winds, density, and other key atmospheric parameters in this critical region. SELMA will provide a high-power, frequency-agile, nearly diffraction-limited laser output at the sodium D2 line in a field-deployable, ruggedized package. In Phase I, OAC will develop a high-power sodium laser prototype and experimentally demonstrate SELMA feasibility.