Improved precision of single-shot temperature measurements by broadband CARS by use of a modeless laser.

The use of a novel modeless laser as the broadband source in multiplex CARS thermometry, by reducing the laser noise on the CARS spectra, is shown to give a precision of approximately 1 % in single-shot temperature measurements in nitrogen at 1200 K.

Multiplex degenerate four-wave mixing in a flame.

The principle of multiplex degenerate four-wave mixing (DFWM) is demonstrated by recording, with a single laser shot, DFWM signals from both D lines of atomic sodium in a seeded flame. Applications of the technique for singleshot temperature measurements for combustion diagnostics are discussed.

Two-dimensional phase-conjugate imaging of atomic distributions in flames by degenerate four-wave mixing.

We report the demonstration of a technique using resonant degenerate four-wave mixing to produce high-resolution, background-free images of atomic distributions in flames. Comparison with laser-induced-fluorescence methods and applications of the method to species of interest in combustion are briefly discussed.