Navigation Links
Small optical force can budge nanoscale objects
Date:11/17/2009

ITHACA, N.Y. - With a bit of leverage, Cornell researchers have used a very tiny beam of light with as little as 1 milliwatt of power to move a silicon structure up to 12 nanometers. That's enough to completely switch the optical properties of the structure from opaque to transparent.

The technology could have applications in the design of micro-electromechanical systems (MEMS) nanoscale devices with moving parts and micro-optomechanical systems (MOMS) which combine moving parts with photonic circuits, said Michal Lipson, associate professor of electrical and computer engineering.

The research by postdoctoral researcher Gustavo Wiederhecker, Long Chen Ph.D. '09, Alexander Gondarenko, Ph.D. '10, and Lipson appears in the online edition of the journal Nature and will appear in a forthcoming print edition.

Light can be thought of as a stream of particles that can exert a force on whatever they strike. The sun doesn't knock you off your feet because the force is very small, but at the nanoscale it can be significant. "The challenge is that large optical forces are required to change the geometry of photonic structures," Lipson explained.

But the researchers were able to reduce the force required by creating two ring resonators circular waveguides whose circumference is matched to a multiple of the wavelength of the light used and exploiting the coupling between beams of light traveling through the two rings.

A beam of light consists of oscillating electric and magnetic fields, and these fields can pull in nearby objects, a microscopic equivalent of the way static electricity on clothes attracts lint.

This phenomenon is exploited in "optical tweezers" used by physicists to trap tiny objects. The forces tend to pull anything at the edge of the beam to be pulled toward the center.

When light travels through a waveguide whose cross-section is smaller than its wavelength some of the light spills over, and with it the attractive force. So parallel waveguides close together, each carrying a light beam, are drawn even closer, rather like two streams of rainwater on a windowpane that touch and are pulled together by surface tension.

The researchers created a structure consisting of two thin, flat silicon nitride rings about 30 microns (millionths of a meter) in diameter mounted one above the other and connected to a pedestal by thin spokes. Think of two bicycle wheels on a vertical shaft, but each with only four thin, flexible spokes. The ring waveguides are three microns wide and 190 nanometers (nm billionths of a meter) thick, and the rings are spaced 1 micron apart.

When light at a resonant frequency of the rings, in this case infrared light at 1533.5 nm, is fed into the rings, the force between the rings is enough to deform the rings by up to 12 nm, which the researchers showed was enough to change other resonances and switch other light beams traveling through the rings on and off.

When light in both rings is in phase the peaks and valleys of the wave match the two rings are pulled together. When it is out of phase they are repelled. The latter phenomenon might be useful in MEMS, where an ongoing problem is that silicon parts tend to stick together, Lipson said.

An application in photonic circuits might be to create a tunable filter to pass one particular optical wavelength, Wiederhecker suggested.


'/>"/>

Contact: Blaine Friedlander
bpf2@cornell.edu
607-254-8093
Cornell University
Source:Eurekalert

Related biology technology :

1. US Government Awards Contract to Bavarian Nordic for the Development of Freeze-Dried IMVAMUNE(R) Smallpox Vaccine
2. Haft Group says Bullish Commodity Market Triggers Small and Micro-cap Upsurge
3. Smallest nanoantennas for high-speed data networks
4. Fate Therapeutics Announces Creation of Small Molecule Platform for Commercial Scale Reprogramming
5. Neogen Again Named to Forbes List of Best Small Companies
6. Small ... smaller ... smallest? ASU researchers create molecular diode
7. Researchers create smaller and more efficient nuclear battery
8. Genedata Screener Supports Small Molecule Research at the Broad Institute of Harvard and MIT
9. New NIST nano-ruler sets some very small marks
10. Poniard Pharmaceuticals Announces Pivotal Phase 3 SPEAR Trial Evaluating Picoplatin in Small Cell Lung Cancer Reaches 320th Event Target
11. Reportlinker Adds Small Molecule Kinase Inhibitors Report
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/27/2016)... ... April 27, 2016 , ... The Pittcon Organizing Committee is pleased to announce ... a volunteer member of Committee since 1987. Since then, he has served in a ... and was chairman for both the program and exposition committees. In his professional career, ...
(Date:4/27/2016)... RESEARCH TRIANGLE PARK, N.C. , April 27, 2016 ... announced today that Martine Rothblatt , Ph.D., Chairman ... an overview and update on the company,s business at ... Conference. The presentation will take place on ... and can be accessed via a live webcast on ...
(Date:4/27/2016)... ... April 27, 2016 , ... PathSensors, Inc., a ... Board. Dr. Lamka will assist PathSensors in expanding the use of the company’s ... the CANARY® test platform for the detection of harmful pathogens, including a number ...
(Date:4/27/2016)... ... 2016 , ... Global Stem Cells Group and the University of ... research and development initiatives for potential stem cell protocol management for 2016 – 2020. ... executives began meeting to establish a working agenda and foster initiatives to promote stem ...
Breaking Biology Technology:
(Date:3/22/2016)... , March 22, 2016 ... research report "Electronic Sensors Market for Consumer Industry by ... & Others), Application (Communication & IT, Entertainment, ... - Global Forecast to 2022", published by ... is expected to reach USD 26.76 Billion ...
(Date:3/17/2016)... -- ABI Research, the leader in transformative technology ... will reach more than $30 billion by 2021, ... electronics, particularly smartphones, continue to boost the biometrics ... two billion shipments by 2021 at a 40% ... Analyst at ABI Research. "Surveillance is also gearing ...
(Date:3/14/2016)... 2016 http://www.apimages.com ) - ... - Renvoi : image disponible via AP Images ... --> DERMALOG, le leader de ... lecteurs d,empreintes digitales pour l,enregistrement des réfugiés en ... pour produire des cartes d,identité aux réfugiés. DERMALOG ...
Breaking Biology News(10 mins):