Absolute calibration of laser-induced fluorescence experiments by optical depth correction

Laser-induced fluorescence measurements are absolutely calibrated by correc tion of relative spatial fluorescence profiles for optical depth. The metho d is applicable if optical depths of fluorescence transitions are sufficien tly high (mean optical depth <(<tau>)over bar>greater than or similar to0.3 ). For calibration two relative spatial density profiles are required. Meas urements of absolute particle densities in a dc glow discharge are performe d and compared to results of laser absorption spectroscopy. Absolute errors are found to be less than 20%. The calibration method is expected to be us eful in experimental environments that are not accessible for other calibra tion methods, e.g., due to high optical depth. (C) 2001 American Institute of Physics.