Measurements of Light Extinction by Single Aerosol Particles

Jim S. Walker, Antonia E. Carruthers, Andrew J. Orr-Ewing*, Jonathan P. Reid

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

23 Citations (Scopus)
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Abstract

A Bessel beam optical trap is combined with continuous wave cavity ringdown spectroscopy to measure the extinction cross section of individual aerosol particles. Particles, similar to 1 mu m in size, can be captured indefinitely and processes that transform size or refractive index studied. The measured light extinction induced by the particle is shown to depend on the position of the particle in the cavity, allowing accurate measurements of the mode structure of a high finesse optical cavity without significant perturbation. The variation in extinction efficiency of a sodium chloride droplet with relative humidity is shown to agree well with predictions from Mie scattering theory.

Original languageEnglish
Pages (from-to)1748-1752
Number of pages5
JournalJournal of Physical Chemistry Letters
Volume4
Issue number10
DOIs
Publication statusPublished - 16 May 2013

Keywords

  • CAVITY RING-DOWN
  • OPTICAL-PROPERTIES
  • REFRACTIVE-INDEX
  • SALT AEROSOLS
  • SCATTERING
  • SPECTROSCOPY
  • SPECTROMETER

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