Method and structure for plasmonic optical trapping of nano-scale particles

Abstract

Methods and article for optically trapping nano-sized objects by illuminating a coaxial plasmonic aperture are disclosed.

Description

STATEMENT OF RELATED CASES[0001]This case is a continuation-in-part of U.S. patent application Ser. No. 14 / 209,904 filed Mar. 13, 2014, which claims priority to U.S. Provisional Patent Application Ser. No. 61 / 779,528 filed on Mar. 13, 2013, both of which applications are incorporated by herein by reference.STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH[0002]This invention was made with Government support under contract FA9550-11-1-0024 awarded by the Air Force Office of Scientific Research. The Government has certain rights in the invention.FIELD OF THE INVENTION[0003]The present invention relates to optical trapping of nano-sized objects.BACKGROUND OF THE INVENTION[0004]Electromagnetic beams can serve as “tweezers,” enabling small objects to be accelerated, manipulated, or trapped using light alone. Optical tweezers were first introduced in 1970, using a laser beam to trap dielectric beads in lower-refractive-index media. Upon interaction with the laser, the bead was both acceler...

AI Technical Summary

Benefits of technology

The patent describes a new device called a coaxial plasmonic aperture that traps particles on the surface of the device, rather than inside it. This means that the trapped particle can be further processed and manipulated. Additionally, the device has higher transmission efficiency compared to previous plasmonic trapping methods, which can result in reduced power requirements.

Problems solved by technology

Despite these advances, optical trapping and manipulation of individual particles with sizes smaller than the wavelength of light remains a considerable challenge.

The problem is inherent to the light beam itself.

If the specimen in question is much smaller than 200 nm, only very loose control of the specimen is possible since, relative to its size, the specimen is being trapped in a much larger potential well.

Furthermore, the optical force that light can exert on an object diminishes as the size of an object decreases.

But there are constraints to increasing intensity; in particular, increased intensity can damage the sample.

But such high optical powers would rapidly burn the particle.

The problem with such an approach is that a molecule might behave quite differently when tethered to what is effectively giant anchor than it would when un-tethered.

However, efficient trapping of sub-10-nm particles still remains a considerable challenge.

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