Microphotography of an electrodynamically levitated microparticle

Steven Arnold, Lorcan M. Folan

Research output: Chapter in Book/Report/Conference proceedingConference contribution


An electrodynamic levitator-trap (Paul trap) is used at line frequency (i.e. 60 Hz) as a sample cell for the long term microphotography of a microparticle in air at STP. Images are obtained in a trap modified to eliminate stray static fields at its AC 'null' point. Resolution in these long term images is found to be limited principally by stochastic thermal fluctuations and optical diffraction. A stochastic differential equation constructed for describing the particle's motion is found to be in good agreement with imaging experiments. This model provides an optimal limit to which a particle may be localized by increasing the drive potential, and indicates that this limit is a function principally of particle size and temperature. Images taken in fluorescence from a glycerol particle containing a probable surfactant are presented. Polarization resolution of these images clearly shows segregation of the molecule to the surface and identifies the orientation of the molecular emission moment in relation to the surface normal.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
PublisherPubl by Int Soc for Optical Engineering
Number of pages5
ISBN (Print)0819410896
StatePublished - 1993
EventLaser Applications in Combustion and Combustion Diagnostics - Los Angeles, CA, USA
Duration: Jan 19 1993Jan 20 1993

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherLaser Applications in Combustion and Combustion Diagnostics
CityLos Angeles, CA, USA

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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