OSA's Digital Library

Virtual Journal for Biomedical Optics

Virtual Journal for Biomedical Optics


  • Editors: Andrew Dunn and Anthony Durkin
  • Vol. 7, Iss. 10 — Oct. 5, 2012

Optimization of probe-laser focal offsets for single-particle tracking

Ai-Tang Chang, Yi-Ren Chang, Sien Chi, and Long Hsu  »View Author Affiliations

Applied Optics, Vol. 51, Issue 23, pp. 5643-5648 (2012)

View Full Text Article

Enhanced HTML    Acrobat PDF (600 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



In optical tweezers applications, tracking a trapped particle is essential for force measurement. One of the most popular techniques for single-particle tracking is achieved by analyzing the forward and backward light pattern, scattered by the target particle trapped by a trap laser beam, of an additional probe-laser beam with different wavelength whose focus is slightly apart from the trapping center. However, the optimized focal offset has never been discussed. In this paper, we investigate the tracking range and sensitivity as a function of the focal offset between the trapping and the probe-laser beams. As a result, the optimized focal offsets are a 3.3-fold radius ahead and a 2.0-fold radius behind the trapping laser focus in the forward tracking and the backward tracking, respectively. The experimental result agrees well with a theoretical prediction using the Mie scattering theory.

© 2012 Optical Society of America

OCIS Codes
(040.0040) Detectors : Detectors
(120.5820) Instrumentation, measurement, and metrology : Scattering measurements
(140.7010) Lasers and laser optics : Laser trapping
(180.3170) Microscopy : Interference microscopy
(290.5850) Scattering : Scattering, particles

ToC Category:
Lasers and Laser Optics

Original Manuscript: January 3, 2012
Revised Manuscript: April 25, 2012
Manuscript Accepted: July 9, 2012
Published: August 2, 2012

Virtual Issues
Vol. 7, Iss. 10 Virtual Journal for Biomedical Optics

Ai-Tang Chang, Yi-Ren Chang, Sien Chi, and Long Hsu, "Optimization of probe-laser focal offsets for single-particle tracking," Appl. Opt. 51, 5643-5648 (2012)

Sort:  Author  |  Year  |  Journal  |  Reset  


  1. L. P. Ghislain and W. W. Webb, “Scanning force microscope based on an optical trap,” Opt. Lett. 18, 1678–1680 (1993). [CrossRef]
  2. L. P. Ghislain, N. A. Switz, and W. W. Webb, “Measurement of small forces using an optical trap,” Rev. Sci. Instrum. 65, 2762–2768 (1994). [CrossRef]
  3. E. L. Florin, J. K. H. Hörber, and E. H. K. Stelzer, “High-resolution axial and lateral position sensing using two-photon excitation of fluorophores by a continuous-wave Nd:YAG laser,” Appl. Phys. Lett. 69, 446–448 (1996). [CrossRef]
  4. M. E. J. Friese, H. Rubinsztein-Dunlop, N. R. Heckenberg, and E. W. Dearden, “Determination of the force constant of a single-beam gradient trap by measurement of backscattered light,” Appl. Opt. 35, 7112–7116 (1996). [CrossRef]
  5. A. Buosciolo, G. Pesce, and A. Sasso, “New calibration method for position detector for simultaneous measurements of force constants and local viscosity in optical tweezers,” Opt. Commun. 230, 357–368 (2004). [CrossRef]
  6. F. Gittes and C. Schmidt, “Signal and noise in micromechanical measurements,” Methods Cell Biol. 55, 129–156 (1998). [CrossRef]
  7. K. Berg-Sørensen and H. Flyvbjerg, “Power spectrum analysis for optical tweezers,” Rev. Sci. Instrum. 75, 594–612 (2004). [CrossRef]
  8. A. Le Gall, K. Perronet, D. Dulin, A. Villing, P. Bouyer, K. Visscher, and N. Westbrook, “Simultaneous calibration of optical tweezers spring constant and position detector response,” Opt. Express 18, 26469–26474 (2010). [CrossRef]
  9. E.-L. Florin, A. Pralle, E. H. K. Stelzer, and J. K. H. Hörber, “Photonic force microscope calibration by thermal noise analysis,” Appl. Phys. 66, S75–S78 (1998). [CrossRef]
  10. A. Rohrbach, C. Tischer, D. Neumayer, E. Florin, and E. Stelzer, “Trapping and tracking a local probe with a photonic force microscope,” Rev. Sci. Instrum. 75, 2197–2210(2004). [CrossRef]
  11. A. Pralle, M. Prummer, E.-L. Florin, E. H. K. Stelzer, and J. K. H. Hörber, “Three-dimensional high-resolution particle tracking for optical tweezers by forward scattered light,” Microsc. Res. Tech. 44, 378–386 (1999). [CrossRef]
  12. W. Singer, S. Bernet, N. Hecker, and M. Ritsch-Marte, “Three-dimensional force calibration of optical tweezers,” J. Mod. Opt. 47, 2921–2931 (2000). [CrossRef]
  13. J. H. G. Huisstede, K. O. van der Werf, M. L. Bennink, and V. Subramaniam, “Force detection in optical tweezers using backscattered light,” Opt. Express 13, 1113–1123 (2005). [CrossRef]
  14. M. Mansuripur, “Distribution of light at and near the focus of high-numerical-aperture objectives,” J. Opt. Soc. Am. A 3, 2086–2093 (1986). [CrossRef]
  15. M. Mansuripur, “Certain computational aspects of vector diffraction problems,” J. Opt. Soc. Am. A 6, 786–805 (1989). [CrossRef]
  16. C. J. R. Sheppard and K. G. Larkin, “Vectorial pupil functions and vectorial transfer functions,” Optik 107, 79–87 (1997).
  17. A. Rohrbach and E. H. K. Stelzer, “Trapping force, force constants, and potential depth for dielectric sphere in the presence of spherical aberrations,” Appl. Opt. 41, 2494–2507 (2002). [CrossRef]
  18. H. C. van de Hulst, “Mie’s formula solution,” in Light Scattering by Small Particles (Dover, 1981), pp. 119–128.
  19. C. F. Bohren and D. R. Huffman, Absorption and Scattering of Light by Small Particles (Wiley, 1983).
  20. B. Ovryn and S. H. Izen, “Imaging of transparent spheres through a planar interface using a high-numerical-aperture optical microscope,” J. Opt. Soc. Am. A 17, 1202–1213 (2000). [CrossRef]
  21. A. Rohrbach and E. H. K. Stelzer, “Three-dimensional position detection of optically trapped dielectric particles,” J. Appl. Phys. 91, 5474–5488 (2002). [CrossRef]
  22. A. Rohrbach, H. Kress, and E. H. K. Stelzer, “Three-dimensional tracking of small spheres in focused laser beams: influence of the detection angular aperture,” Opt. Lett. 28, 411–413 (2003). [CrossRef]
  23. M. Speidel, L. Friedrich, and A. Rohrbach, “Interferometric 3D tracking of several particles in a scanning laser focus,” Opt. Express 17, 1003–1015 (2009). [CrossRef]
  24. G. Volpe, G. Kozyreff, and D. Petrov, “Backscattering position detection for photonic force microscopy,” J. Appl. Phys. 102, 084701 (2007). [CrossRef]

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited