Abstract

There are many problems in combustion science in which it is critically important to have high temporal, spatial, and temporal resolution of species concentrations. These nontrivial requirements are found in situations as diverse as fundamental studies of laboratory flame structure to the emissions of products of incomplete combustion from hazardous waste incinerators. Traditional probe sampling and analysis methods are limited to spatial regions that are relatively free of particulate matter. With some exceptions, many of the optical diagnostics methods employed so far are not quantitative, and may also suffer interferences from particulates and/or polynuclear aromatic hydrocarbons. The mid-infrared region (3–16 μm) provides an advantageous slice of the electromagnetic spectrum for these measurements: nearly every molecule absorbs light here. However, because of the high density of states here, only after the advent of narrow frequency lasers has it been possible to observe isolated spectral features in reactive media.

© 1991 Optical Society of America