Self-regularization in dual beam fiber traps:

Dual beam fiber traps consisting of two opposing single-mode fiber ends emitting counter-propagating (mutually incoherent) near-infrared beams are an attractive tool to study multi-particle interactions. Especially if the trapped micro-particles influence each other (optical binding regime).

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Fig. 1 Micro-Abacus (dual fiber trap plus single-beam tweezers).

Physically rich behaviour can be observed, depending on parameters such as particle size compared to wavelength, viscosity or refractive index.

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Fig. 2 Self-regularization in a dual fiber trap.

In some regimes characterized by strong influence of the particles on each other by means of their light scattering, striking self-regularization effects may be observed, e.g. the spontaneous formation of a (quasi-) equidistant chain of particles (see movie above).


W. Singer, S. Bernet, M. Ritsch-Marte: Self-organized array of regularly spaced microbeads in a fiber-optical trap, J. Opt. Soc. Am. B 20, 1568-1574 (2003).