Free space laser plasmas as scattering and reflection elements for standoff IR spectroscopy

Femtosecond laser filamentation can serve as an enabling technology for remote sensing in the analysis of remote materials and atmospheric trace species. We propose the use of free space laser plasmas produced in atmosphere as controllable standoff scattering and reflection elements for the dynamic redirection and collection of spectroscopic signatures. In this study, we characterize the scattering properties of laser plasmas to infrared laser light in the range 1.9μm to 4.4μm and at 10.6μm. For the first time, a spectroscopic measurement is conducted by measuring backscattered light from a free space laser plasma. Plasma reflected tunable laser absorption spectroscopy for quantitative measurement of CO2 concentration is reported.