Recording long-term optical images of a Brownian particle in a Paul trap essentially free of thermally induced positional noise

S. Arnold, J. H. Li, S. Holler, A. Korn, A. F. Izmailov

Research output: Contribution to journalArticle


We show experimentally that the positional uncertainty in long-term images of a microparticle in a Paul trap in air can be reduced to the optical limit, and below the pseudopotential limit. For this damped system, far below any Mathieu instability, the particle's thermally induced positional noise is extremely sensitive to the phase of the driving field. Accumulating images strobed at the proper phase produces a long-term optical image which is essentially free of thermally induced positional noise. Although noise squeezing theory does not apply at such large dissipation, our results may be understood through recent theory of the Brownian parametric oscillator. Use of this theory coupled with our observations suggests that the extreme reduction in spatial variance observed by using our technique results from working in a low Reynolds number regime.

Original languageEnglish (US)
Pages (from-to)3566-3571
Number of pages6
JournalJournal of Applied Physics
Issue number6
StatePublished - Dec 1 1995


ASJC Scopus subject areas

  • Physics and Astronomy(all)

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