Molecular Spectroscopy of a Single Aerosol Particle
S. Arnold, M. Neuman, and A.B. Pluchino
Opt. Lett. 9, 4-6(1984)

The absorption spectrum of a single micrometer-sized aerosol particle is measured for the first reported time in the IR. Particle absorption is determined through the IR modulation of visible scattered light near a structure resonance. This technique, termed structure resonance modulation spectroscopy, is used to measure the IR absorption spectrum of an (NH4)2SO4 aerosol droplet of 5.4um diameter in the region from 970 to 1280 cm^-1. The resulting spectrum, when fitted by Mie theory, enables one to determine the molecular composition of the droplet.