Multi-color holographic optical trapping
AssigneeNew York University
InventorDavid G. Grier
Life of this patent
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Abstract
A method and apparatus for selecting a specific fraction from a heterogeneous fluid-borne sample using optical gradient forces in a microfluidic or fluidic system are presented. Samples may range in size from a few nanometers to at least tens of micrometers, may be dispersed in any fluid medium, and may be sorted on the basis of size, shape, optical characteristics, charge, and other physical properties. The selection process involves passive transport through optical intensity field driven by flowing fluid, and so offers several advantages over competing techniques. These include continuous rather than batch-mode operation, continuous and dynamic tunability, operation over a wide range of samples, compactness, and low cost.
Claims19
A method for creating holographic optical traps of different color by an optical system having a focal plane generating at least one light beam provided to an input aperture and passing the at least one light beam through a diffractive optical element, the improvement characterized by separating one color from another color in the light beam passed through the diffractive optical element;
- creating a holographic optical trap from each of the separated colors;
- and
- projecting each separate color of holographic optical traps in accordance with a different phase modulation associated with the diffractive optical element, thereby enabling a separate projection of a different attern for each of the separate colors of the holographic optical traps for a different selected purpose.
An apparatus for creating a plurality of optical traps of different color with the apparatus including a laser beam source to provide a first and second laser beam and a diffractive optical element, the improvement characterized by an optical system for separating one color from another color in each of the first and the second laser beams and an optical element to project optical traps of the one color spatially separate from the second color and wherein the diffractive optical element is programmed to apply a first phase modulation of the one color and a second phase modulation to the another color, thereby resulting in projection of separate patterns, each of the separate patterns having one color and different than the other pattern.
Dependencies are inferred from the claim text.