Quantum cascade laser spectroscopy-based high-sensitive temperature measurement technology

Abstract

The development of temperature sensors with ultra-fast response, high sensitivity, and wide range of temperature is of important academic value for the study of flame structure and combustion characteristics under extreme conditions. Recently, tunable diode laser absorption spectroscopy (TDLAS) is developed rapidly as an important means of combustion diagnostics due to its outstanding characteristics, such as non-invasiveness, rapid response, and high realizability. The absorption lines of TDLAS are extended to the mid-infrared region. Two spectral lines of H2O at center wavelength of 2136.14 and 1874.31 cm − 1 are used as candidate pair, which provides a wide measuring range (800 to 4000 K) and high-temperature sensitivity (4.55 at 1000 K) sensor for temperature measurement. We used two quantum cascade lasers with wavelength of 4.68 and 5.34 μm to scan the selected line pair of H2O rapidly in the combustion environment and obtained the temperature information of the combustion field. Our work provides a good solution for the temperature measurement of extreme combustion environment with ultra-fast response, high sensitivity, and wide temperature range.