Abstract
We construct a carbon dioxide sensing system with a 2.0μm DFB Laser, the sensitivity of this system is about 10-8 W / Hz1/2cm。In addition, we observe the 4.3 μm fluorescence by (2001)-(2000) and give a basic study on 4.3μm fluorescence spectroscopy. In addition, we construct a cavity-enhancement spectrometer for future frequency stabilization. So far the cavity resonance frequency can just maintain oscillation around laser frequency center for tens seconds.