Resonance Effects in Optical Trapping Export

@inproceedings{citeulike:3393304, abstract = {In optical trapping a particle is trapped in a laser focus by forces generated by the refraction of the laser light by the particle. The strength of these forces depends on the real part of the refractive index of the particle (relative to the medium). The imaginary part of the refractive index is not directly of influence to the trapping, but is responsible for the absorption of light. However, real and imaginary part are related by the Kramers-Kronig relation: on the red side of a resonant absorption band the (real) refractive index is increased, on the blue side decreased. In this contribution we investigate both experimentally and theoretically whether this effect can be used to enhance optical trapping of (dye-doped) beads with laser light just red of the absorption band of the bead. Using classical electromagnetic theory, we estimate that trapping can be enhanced up to 50-fold near optical resonance. We also show experiments in which we test the effect of dyes on the trapping of polystyrene beads. In the experiments we compare the trapping of dye-doped and undoped beads as a function of the laser wavelength of the trapping laser close to the absorption band of the bead.}, author = {Peterman, E. J. G. and Agayan, R. R. and Gittes, F. and Kopelman, R. and Schmidt, C. F.}, citeulike-article-id = {3393304}, citeulike-linkout-0 = {http://meeting.biophysj.org/cgi/content/citation/82/1/496/b}, day = {1}, journal = {Biophysical Journal (Annual Meeting Abstracts)}, keywords = {optical, resonance, trap, tweezers}, month = {January}, number = {1}, pages = {496}, posted-at = {2008-10-10 14:17:46}, priority = {0}, title = {Resonance Effects in Optical Trapping}, url = {http://meeting.biophysj.org/cgi/content/citation/82/1/496/b}, volume = {82}, year = {2002} }

TY - CONF ID - citeulike:3393304 L3 - citeulike-article-id:3393304 N2 - In optical trapping a particle is trapped in a laser focus by forces generated by the refraction of the laser light by the particle. The strength of these forces depends on the real part of the refractive index of the particle (relative to the medium). The imaginary part of the refractive index is not directly of influence to the trapping, but is responsible for the absorption of light. However, real and imaginary part are related by the Kramers-Kronig relation: on the red side of a resonant absorption band the (real) refractive index is increased, on the blue side decreased. In this contribution we investigate both experimentally and theoretically whether this effect can be used to enhance optical trapping of (dye-doped) beads with laser light just red of the absorption band of the bead. Using classical electromagnetic theory, we estimate that trapping can be enhanced up to 50-fold near optical resonance. We also show experiments in which we test the effect of dyes on the trapping of polystyrene beads. In the experiments we compare the trapping of dye-doped and undoped beads as a function of the laser wavelength of the trapping laser close to the absorption band of the bead. IS - 1 JF - Biophysical Journal (Annual Meeting Abstracts) EP - 496 TI - Resonance Effects in Optical Trapping VL - 82 SP - 496 KW - optical KW - resonance KW - trap KW - tweezers AU - Peterman, EJG AU - Agayan, RR AU - Gittes, F AU - Kopelman, R AU - Schmidt, CF PY - 2002/01/01/ UR - http://meeting.biophysj.org/cgi/content/citation/82/1/496/b ER -