Rotational CARS: a comparison of different techniques with emphasis on accuracy in temperature determination.

Different rotational CARS techniques have been evaluated in terms of single-shot temperature accuracy and signal intensity in room temperature nitrogen and in flames. The different techniques include both dual broadband techniques, using one or two broadband dye lasers, and conventional rotational CARS with different dye lasers. These techniques are also compared with vibrational CARS concerning temperature accuracy and with theoretical predictions. The results indicate that the dual broadband techniques are to be preferred over conventional rotational CARS and also over vibrational CARS at room temperature. At flame temperatures the vibrational CARS technique seems to be the technique yielding highest temperature accuracy. The experimental results are also generally in good agreement with the calculated values.