Sorting of polystyrene microspheres using a Y-branched optical waveguide

Abstract

Abstract:We demonstrate how a Y-branched optical waveguide can be used for microparticle sorting. Polystyrene microparticles, optically guided in the waveguide's evanescent field, are directed down the desired, more strongly illuminated, output branch. The output of a fibre laser at a wavelength of 1066 nm is coupled to the waveguide by direct butting. The power distribution between the two output branches is selected by the relative position of the fibre to the waveguide input facet. This provides a simple method for reliable particle sorting with very high probability of success under appropriate conditions. The method can be easily combined with other particle manipulation techniques of interest for micro total analysis systems of the future.

Dielectric microsphere manipulation and chain assembly by counter-propagating waves in a channel waveguide

“…Using the evanescent field of a waveguide as a manipulation tool allows us to exploit a variety of integrated optics structures. One example is using Y-branched waveguides to sort microparticles, as demonstrated earlier [5]. When a particle solution is introduced in the waveguide cover region, particles interact with the waveguide's evanescent field.…”

Velocity distribution of Gold nanoparticles trapped on an optical waveguide

“…The optical propulsion of gold or dielectric particles on an optical waveguide has been reported by several groups [1][2][3][4][5][6][7], with proposed applications in sorting of biological species [1,7,8] and in chemical sensing by surface enhanced Raman spectroscopy [9]. Kawata and Tani first demonstrated the propulsion of 0.5µm gold and 1µm platinum particles on waveguides [3].…”

Serial Raman spectroscopy of particles trapped on a waveguide

“…The technique uses the evanescent field generated above the waveguide to propel the objects along the waveguide path and thus provides excellent control over the translational movement of particles without exposure to high optical intensities. Sorting and assembly line-like transportation have been demonstrated, either using Y-branched waveguides or combined with microfluidics [5,6]. However, information on the trapped particles, besides size or refractive index estimates, is not provided by the waveguide trapping technique itself.…”