Abstract

In trace gas detection on absorption spectroscopy there is a need for widely tunable narrow bandwidth mid infrared light sources. Until now no commercial available laser system full fills these necessary requirements in the wavelength range between 3 – 4µm, where Methane, a strong greenhouse gas has his strongest absorption lines. Since the availability of specially poled nonlinear crystals like PPLN different spectrometer based different frequency generation between NIR diode lasers or diode laser pumped solid state lasers have been demonstrated [1]

© 2000 IEEE