Abstract

Detection of chemical species using differential absorption lidar is a topic of growing interest for safety in petrochemical facilities, outdoor air quality measurements, greenhouse gases monitoring from space, and standoff detection of toxic chemical plumes. In such a lidar the optical source must combine a high energy (> 10 mJ for range-resolved detection), a wide and arbitrary wavelength tunability, and a very narrow linewidth (<0.1 cm⁻¹ or even single-frequency for the most demanding applications). In the longwave infrared (8–12 µm), this challenge is even more difficult due to the scarcity of mature optical components. Here, we propose a solution based on optical parametric conversion, using a master-oscillator power-amplifier (MOPA) concept. The design, shown in Fig.1, follows our previous work on a high-energy single-frequency emitter near 2 µm [1], and is similar to one previously proposed for LWIR emission [2].

© 2017 IEEE