Fundamentals
Optical forces | Force fields | Lorentz force distribution in media | Modeling
Figure 2: Experiments by Fournier et al.
in the early 1990’s demonstrated laser
trapping of arrays of macroscopic
particles along interference fringes:
M. Burns, J.-M. Fournier, and J. A.
Golovchenko, Science 249, 749 (1990).
Force field
The manipulation of the incident field can, by means of optical forces, be used to organize particles in various patterns.
A single laser beams yields a single trap, close to its waist, yielding an optical tweezer. Two coherent laser beams yield sinusoidal interference fringes, in which particles can be trapped, forming lines of matter [Fig. 1]. Three coherent laser beams with equal angular separation and equal amplitudes yield an hexagonal interference pattern, also able to trap multiple particles [Fig. 2].
References
- M. Burns, J-M. Fournier and J. Golovchenko, Optical binding, Phys. Rev. Lett., 1989.
- M. Burns, J-M. Fournier and J. Golovchenko, Optical matter: Crystallization and binding in intense optical fields, Science, 1990.
