Researchers cool semi membrane by laser interaction
January 24, 2012 // Nicolas Mokhoff
Researchers at the Niels Bohr Institute, University of Copenhagen, have discovered a new method for laser cooling semiconductor membranes-—by heating the membrane.
Researchers were able to experimentaly cool membrane fluctuations to minus 269 degrees C.
In the experiment a gallium arsenide semiconductor membrane with a thickness of 160 nanometers and a surface area of 1 x 1 mm was made to interact with the laser light in such a way that its mechanical movements affected the light that hit it.
"We carefully examined the physics and discovered that a certain oscillation mode of the membrane cooled from room temperature down to minus 269 degrees C, which was a result of the complex and fascinating interplay between the movement of the membrane, the properties of the semiconductor and the optical resonances,” explained Koji Usami, associate professor at Quantop at the Niels Bohr Institute, in a statement.
The experiment consisted of shining the laser light onto the nanomembrane in a vacuum chamber. When the laser light hits the semiconductor membrane, some of the light is reflected and the light is reflected back again via a mirror in the experiment so that the light flies back and forth in this space and forms an optical resonator. Some of the light is absorbed by the membrane and releases free electrons. The electrons decay and thereby heat the membrane and this gives a thermal expansion. In this way the distance between the membrane and the mirror is constantly changed in the form of a fluctuation, according to Usami.
"The paradox is that even though the membrane as a whole is getting a little bit warmer, the membrane is cooled at a certain oscillation and the cooling can be controlled with laser light," said Usami.
Researchers believe that efficient cooling of mechanical fluctuations of semiconducting nanomembranes by means of light could lead to the development of new sensors for electric current and mechanical forces, and could replace expensive cryogenic cooling used today.
The experiment results are published in the scientific journal, Nature Physics.
Philips offloads LED lighting components unit for USD2.8bn
March 31, 2015
Philips has agreed to sell an 80.1 percent stake in the company's lighting components division for $2.8 billion to Go Scale ...
Imec and sureCore partners on 28nm SRAM
Analysts cool on Intel/Altera combo
A new candidate for ultra-thin optoelectronics: DNA-peptide
KIT, Schaeffler optimise power steering for electric cars
Never lose track of things
March 30, 2015
This month, DecaWave is offering EETimes Europe's readers the chance to win two TREK1000 kits to evaluate its Ultra-Wideband ...
Europe leads PV uptake charts as global growth continues
Graphene's first commercial success: energy-saving light bulbs?
Nanolaser enables on-chip photonics
- New Linear Regulators Solve Old Problems
- Intelligent Over Temperature Protection for LED Lighting Applications
- Intel helps to Turbocharge Infotainment Systems Designs
- High Performance Portable DC Bench Power Supply: Save Money and Free Up Bench Real Estate by Building Your Own
InterviewInfineon: CAN FD success goes at the expense of FlexRay
The faster version of the venerable CAN bus, CAN FD is currently taking off at several carmakers. Infineon's Thomas Böhm, Head of Body / Automotive, believes this could well go at the expense of FlexRay. ...
Filter WizardCheck out the Filter Wizard Series of articles by Filter Guru Kendall Castor-Perry which provide invaluable practical Analog Design guidelines.
Linear video channel
READER OFFERRead more
This month, DecaWave is offering EETimes Europe's readers the chance to win two TREK1000 kits to evaluate its Ultra-Wideband (UWB) indoor location and communication DW1000 chip in different real-time location system topologies.
Worth €947, the kit allow designers to prove a concept within hours and have a prototype ready in days. Based on the two-way ranging scheme, the kit lets you test...MORE INFO AND LAST MONTH' WINNERS...
December 15, 2011 | Texas instruments | 222901974
Unique Ser/Des technology supports encrypted video and audio content with full duplex bi-directional control channel over a single wire interface.