CO2 Gas Temperature Sensing near Room Temperature by a Quantum Cascade Laser in Inter Pulse Mode

A non-invasive CO2 gas temperature sensing technique at or close to the room range based on quantum cascade laser absorption spectroscopy is presented. The method probes thermally populated ground state and hot-band rotational-vibrational transitions of in frequency from 2349 2351 cm−1 which obtained Boltzmann statistics. Transmission spectra are recorded by injection-current driven frequency-scans, so-called inter pulse mode, a pulsed distributed feedback laser. statistical uncertainty (1σ) for single scans with time resolution 10 ms 4 K can be further reduced down ∼50 mK long-time averaging about 1 min. evaluated particular emphasis implementation, data acquisition, analysis potential improvements.