Evaluation of temperature and concentration in H₂N₂ dual‐pump CARS spectra using the Keilson and Storer three‐dimensional model for H₂ Q‐branch

Abstract

Coherent anti-Stokes Raman scattering (CARS) is a widely accepted standard for thermometry in combustion environments.Accurate lineshape models are of crucial importance for the computation of CARS spectra used for temperature and concentration evaluations. Therefore, a new lineshape model for the H 2 molecule is developed and tested for ambient pressure applications. Measurements were taken in a heated cell and in a partially premixed flame with dual-pump CARS techniques, respectively. Line broadening coefficients for H 2 -N 2 mixture are calculated using the new speed memory effects model. The experimental vibrational-CARS (VCARS) spectra were evaluated with this new lineshape model and the temperature and relative H 2 concentration results were compared with an already existing model.

Advances in nonlinear optical spectroscopies: a historical perspective of developments and applications presented at ECONOS

“…Bonamy and co‐workers have been leading in the theoretical development of linewidth models. In collaboration with experimentalists they studied collisions of molecular nitrogen with a number of partners such as H 2 , CO, CO 2 , H 2 O, O 2 , C 2 H 2 , and collisions with itself, over wide temperature and pressure ranges. In recent years, nitrogen collisions have been studied using time‐domain CARS with femtosecond lasers.…”

Recent advances in linear and nonlinear Raman spectroscopy. Part IV

“…Accurate line shape models are of crucial importance for the computation of CARS spectra used for temperature and concentration evaluations. Gao et al [126] presented a new line shape model for molecular H 2 that was developed and tested for ambient pressure applications. In a related paper, Bohlin et al [127] published an improvement of rotational CARS thermometry for fuel-rich hydrocarbon flames by inclusion of N 2 -H 2 Raman line widths.…”

New trends and recent advances in coherent Raman microscopy and nonlinear optical spectroscopy: introduction to the special issue

“…[13,14] A focus here is on CARS as a powerful tool for gas-phase diagnostics and thermometry. [15,16] This special issue bears witness to the fact that spectroscopy in a traditional manner forms the basis of CARS microscopy, whereas advanced schemes derived from the versatility of femtosecond pulse shaping have an increasing impact on both CARS spectroscopy and microscopy. [17 -20] The CARS work is beautifully supplemented in this special issue by contributions presenting significant advances in ultrafast nonlinear techniques [21] and four-wave mixing applications and methodology.…”