A Comprehensive Review of Optical Systems for Soot Volume Fraction Measurements in Co-Flow Laminar Flames: Laser-Induced Incandescence (LII) and Laser Extinction Method (LEM)

Laser-Induced Incandescence (LII) has been widely acknowledged as a highly effective method for measuring soot in co-flow laminar flames. Conversely, quantitative assessments of soot volume fraction (SVF) are achievable through the Laser Extinction Method (LEM). This comprehensive review centers on the optical systems and experimental parameter configurations employed in LII and LEM measurements. Subsequently, several pivotal parameters specific to LII and LEM, such as laser fluence and detection wavelength, are individually discussed. Furthermore, this review showcases current experimental arrangements utilized for LEM measurements. In addition, recommendations are provided for the execution of planar LII and LEM measurements. Lastly, a summarized analysis and discussion pertain to an optical system capable of jointly measuring LII and LEM.