Microdroplet identification and size measurement in sprays with lasing images

Two-dimensional fluorescence and lasing images of a Rhodamine-6G doped water spray are observed with color photography. The lasing microdroplets are identified by their two reciprocal lasing spots. The microdroplet sizes are measured using the digitized images. The measured mean microdroplet diameter is 69.7 mum with a standard deviation of 23.1 mum. The measured microdroplet size distribution compares favorably with the normal Gaussian size distribution. (C) 2002 Optical Society of America