Simultaneous measurement of temperature and water concentration using a novel laser dispersion spectrum extraction method immune to carrier phase variation

Measurement of CO2 Isotopologue Ratios Using a Hollow Waveguide-Based Mid-Infrared Dispersion Spectrometer

“…Unlike CLaDS, which requires a high-performance real-time spectrometer to perform frequency demodulation of the beat signal and a more complex data acquisition system, HPSDS directly retrieves the phase of the down-converted beat signal through a lock-in amplifier. 36,37 In contrast to CLaDS, HPSDS has a simpler optical setup and signal processing system. To the best of our knowledge, there are currently no literature reports on HWG-based HPSDS measurements of CO 2 isotopes.…”

“…As field-deployable gas detection technologies, both CLaDS and HPSDS are based on the high-frequency intensity modulation of the laser output to retrieve dispersion distributions. − Since the measured quantity is phase-shift independent of light intensity, they are not affected by fluctuations in laser power. Unlike CLaDS, which requires a high-performance real-time spectrometer to perform frequency demodulation of the beat signal and a more complex data acquisition system, HPSDS directly retrieves the phase of the down-converted beat signal through a lock-in amplifier. , In contrast to CLaDS, HPSDS has a simpler optical setup and signal processing system. To the best of our knowledge, there are currently no literature reports on HWG-based HPSDS measurements of CO 2 isotopes.…”