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Optics Letters

Optics Letters


  • Editor: Alan E. Willner
  • Vol. 34, Iss. 3 — Feb. 1, 2009
  • pp: 277–279

Beyond the frame rate: measuring high-frequency fluctuations with light-intensity modulation

Wesley P. Wong and Ken Halvorsen  »View Author Affiliations

Optics Letters, Vol. 34, Issue 3, pp. 277-279 (2009)

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Power-spectral-density measurements of any sampled signal are typically restricted by both acquisition rate and frequency response limitations of instruments, which can be particularly prohibitive for video-based measurements. We have developed a new method called intensity modulation spectral analysis that circumvents these limitations, dramatically extending the effective detection bandwidth. We demonstrate this by video tracking an optically trapped microsphere while oscillating an LED illumination source. This approach allows us to quantify fluctuations of the microsphere at frequencies over 10 times higher than the Nyquist frequency, mimicking a significantly higher frame rate.

© 2009 Optical Society of America

OCIS Codes
(120.4820) Instrumentation, measurement, and metrology : Optical systems
(170.4520) Medical optics and biotechnology : Optical confinement and manipulation
(110.4155) Imaging systems : Multiframe image processing

ToC Category:
Instrumentation, Measurement, and Metrology

Original Manuscript: October 16, 2008
Revised Manuscript: November 21, 2008
Manuscript Accepted: November 26, 2008
Published: January 26, 2009

Virtual Issues
Vol. 4, Iss. 4 Virtual Journal for Biomedical Optics

Wesley P. Wong and Ken Halvorsen, "Beyond the frame rate: measuring high-frequency fluctuations with light-intensity modulation," Opt. Lett. 34, 277-279 (2009)

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