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-óby 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.
Mars Probe Looks for Atmosphere 'Lost in Space'
September 21, 2014
NASA's latest Martian probe is fast approaching the Red Planet to begin exploring for the first time its upper atmosphere, ...
Sensor Hubs Aided by IEEE-2700-2014 Datasheets
Daimler to test autonomous driving in California
Can plant-based batteries be a viable option?
Structural electronics - the next big thing in smart cars?
Elastomeric camouflage switches texture and colour
September 18, 2014
Finding their inspiration from nature's most skillful camouflage artists such as octopuses, squids, and cuttlefishes, MIT ...
Solar microinverter to break USD1bn barrier in 2018
7nm EUV could ease 10nm squeeze, says ASML
Europeans flex skills to commercialize OLED and OPV devices
- Putting FPGAs to Work in Software Radio Systems Handbook
- Flexible and Low Power Driving of Solenoid Coils
- How to Protect & Monetize Android Apps
- Power Modules: The New Super Power
InterviewCEO interview: AMS' Laney on driving a sensor-driven business
Kirk Laney, CEO of Austrian mixed-signal chip and sensor company AMS, wants to leverage the opportunity that technology affords to create new markets for sensors and sensor interfaces.
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, Trinamic Motion Control is offering you to win one of four TMCM-1043 development kits for its highly integrated, NEMA 17-compatible TMCM-1043 stepDancer stepper motor module.
Offering designers an easy-to-use PC-based GUI that allows one-click modification of motor drive current, micro-stepping and other key parameters, the intuitive kits are custom designed and developed for...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.