Fiber based optical trapping of aerosols

Abstract

We present the use of optical fibers to form a counter-propagating optical trap as a means of manipulating both solid and liquid aerosols. We explore the use of single and multimode fibers to achieve trapping of various particles in air, present the trapping properties of the different fiber types and compare the observed trends to those predicted by theory. Using fibers, we are able to hold suspended particles for extended periods of time and to precisely manipulate them over distances of several hundred microns. We discuss the difficulties and advantages of each fiber configuration and conclude with a demonstration that fiber based trapping offers a good candidate for studying optical binding in air.

Optical Manipulation of Microparticles in an SU-8/PDMS Hybrid Microfluidic Chip Incorporating a Monolithically Integrated On-Chip Lens Set

“…2, is used to achieve a light-beam-waist radius of 50 µm, and another on-chip lens set on the opposite side is used to achieve a light-beam-waist radius of 10 µm. The use of the two counterpropagating light beams is different from the optical trapping reported in [32], where a pair of single-mode fibers or a pair of multimode fibers was used to achieve the optical trapping. However, in this paper, the optical manipulation of a microparticle is performed by the optofluidic transport, which is different from the optical trapping.…”

“…In addition, the optical manipulation ability is important for the assembly techniques and optically driven bioanalytics [33]. Furthermore, the analysis of the mode distribution in the cross section of the two light beams and the precise control of their output power, as required for the optical trapping in [32], are not necessarily considered in the proposed optical manipulation scheme, because we are only considering the mean value of the radiation forces, as illustrated in (2). Therefore, it is a simple process to achieve optical manipulation.…”

Optical Binding Phenomena: Observations and Mechanisms

“…• aerosol trapping: recent preliminary results have reported optical trapping and binding of aerosol particles in air [26,27,28,29,30].…”

Doppler Cooling a Microsphere

“…An efficient optical trap for dielectric microspheres is produced by two diverging counter-propagating fields in a two-beam fiber trap [30]. A single collimated beam that is red detuned from resonance could be used to cool the trapped sphere in analogy to the Doppler cooling of a trapped ion.…”