| Popis: |
A Dual differential absorption LIDAR (DIAL) based on two stage tandem OPO midinfrared (IR) tunable Optical Parametric Oscillator (OPO) has been developed and characterized. The first OPO stage, built around a nonlinear KTP crystal in an unstable resonator, produces 40 mJ of 1.57 μm radiation when pumped by a Q-switched Nd:YAG laser. Silver gallium selenide (AgGaSe2) crystal forms the OPO second stage which generates 0.9 mJ of Idler peak energies within 5.0 to 11.0 μm tuning region with typical spectral bandwidth values of the mid-IR radiation of 7-8 cm-1 which is well-matched with many complex molecules in the atmosphere which have bandwidths larger than 15 cm-1. The receiver is composed of a gold-plated primary mirror of a 300 mm forms the Cassegrain telescope, two channel detection system and control and amplifying electronics. Preliminary path-averaged ammonia concentration measurements are presented and analyzed. |
