Mid-infrared supercontinuum laser source for hydrometeors extinction measurements

Supercontinuum laser sources have been launched on the market for more than 10 years. Mainly based on the use of silica-based photonic crystal fiber, these sources are available today from various manufacturers with blue-UV to IR spectral coverage. These lasers are used for applications in biology, metrology, or spectroscopy. Because of the silica absorption, spectra are limited to 2500 nm with a pump laser at 1064 nm and up to 2800 nm with a pump laser at 1550 nm. New applications require the use of larger wavelengths in the mid-infrared region (Mid-IR). Recent developments in fluoride glass fibers permit nowadays to generate mid-infrared supercontinuum sources covering a wide spectrum from 800 nm to at least 4100 nm, with high average power. This source turns out to be of great interest for measuring broadband extinction of gases and particles such as aerosols and hydrometeors.