Stories tagged laser

Jun
28
2012

Sensing Strain: This new system will allow you to detect strain anywhere, in any direction, and at any time.
Sensing Strain: This new system will allow you to detect strain anywhere, in any direction, and at any time.Courtesy Bruce Weisman
Scientists at Rice University developed a new type of paint, infused with carbon nanotubes, that can detect strain in bridges, buildings, and airplanes before the signs of deformation become visible to the naked eye.

This is how it works: The paint is applied to the desired structure and allowed to dry. A laser beam is then focused on the structure, which excites the carbon nanotubes, and in turn, causes them to fluoresce in a way that indicates strain. Finally, a handheld infrared spectrometer is used to measure this fluorescence.

The advantage of strain paint over conventional strain gauges is that the gauge (the paint, in this case) and the read-out device don't have to be physically connected. Also, strain paint allows you to measure strain anywhere on the structure, and along any direction. This product is not yet on the market, but it will benefit all of us, as I'm sure we all find the structural integrity of our planes, bridges, and buildings to be pretty important.

Feb
21
2010

Smallest LASER ever

Nanolaser: Image shows the nanolaser design: a gold core surrounded by a glasslike shell filled with green dye
Nanolaser: Image shows the nanolaser design: a gold core surrounded by a glasslike shell filled with green dyeCourtesy Birck Nanotechnology Center, Purdue University

Lasers, now used in CD and DVD players and to read prices at the checkout counter, were first developed about fifty years ago. They work by resonating light between two reflectors. They cannot be made smaller than half a wavelength of light, though (about 200 nanometers).

SPASERs

Researchers have now figured a way to force a sphere of only 44 nanometers to emit laser light (more than 1 million could fit inside a red blood cell). These nano-lasers are called spasers which stands for "surface plasmon amplification by stimulated emission of radiation".
When light is pumped onto the sphere, the surface coating generates a form of radiation called surface plasmons.

To act like lasers, they require a "feedback system" that causes the surface plasmons to oscillate back and forth so that they gain power and can be emitted as light.Plasmon resonances are capable of squeezing optical frequency oscillations into a nanoscopic cavity to enable a true nanolaser
Purdue University

Nanophotonics and nanoplasmonics

This new area of technology sometimes called nanophotonics or nanoplasmonics will enable better microscopes, smaller computer memories, faster computer circuits that use light instead of electrons, and many more yet to be imagined applications.

Read the research papers

This current work on spasers is published in the journal Nature: Applied physics: Lasers go nano
Demonstration of a spaser-based nanolaser

Researchers at the University of California in partnership with Intel, have produced a computer chip that can communicate using lasers instead of wires. This chip is built with silicon and conventional manufacturing processes making it relatively cheap but 100s of times faster than current chips. Will this change how we compute?