Lawrence Livermore National Laboratory scientists have for the first time converted the highest frequency sounds into light by reversing a process that converts electrical signals to sound.
Commonly used piezo-electric speakers, such as those found in a cell phone, operate at low frequencies that human ears can hear.
But by reversing that process, lead researchers Michael Armstrong, Evan Reed and Mike Howard, LLNL colleagues, and collaborators from Los Alamos National Laboratory and Nitronex Corp., used a very high frequency sound wave - about 100 million times higher frequency than what humans can hear - to generate light.
“This process allows us to very accurately ‘see’ the highest frequency sound waves by translating them into light,” Armstrong said.
The research appears in the March 15 edition of the journal Nature Physics.
During the last decade, pioneering experiments using sub-picosecond lasers have demonstrated the generation and detection of acoustic and shock waves in materials with terahertz (THz) frequencies. These very same experiments led to a new technique for probing the structure of semiconductor devices.
However, the recent research takes those initial experiments a step further by reversing the process, converting high-frequency sound waves into electricity. The researchers predicted that high frequency acoustic waves can be detected by seeing radiation emitted when the acoustic wave passes an interface between piezoelectric materials.
Very high-frequency sound waves have wavelengths approaching the atomic-length scale. Detection of these waves is challenging, but they are useful for probing materials on very small length scales.
But that’s not the only application, according to Reed.
“This technique provides a new pathway to generation of THz radiation for security, medical and other purposes,” he said. “In this application, we would utilize acoustic-based technologies to generate THz.” Security applications include explosives detection and medical use may include detection of skin cancer.
And the Livermore method doesn’t require any external source to detect the acoustic waves.
“Usually scientists use an external laser beam that bounces off the acoustic wave – much like radar speed detectors – to observe high frequency sound. An advantage of our technique is that it doesn’t require an external laser beam – the acoustic wave itself emits light that we detect,” Armstrong said.
Founded in 1952, Lawrence Livermore National Laboratory is a national security laboratory, with a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by Lawrence Livermore National Security, LLC for the U.S. Department of Energy's National Nuclear Security Administration.
Anne Stark | EurekAlert!
Further reports about: > Computer Chips > LEDs > Security Forum > THz > acoustic and shock waves > acoustic waves > atomic-length scale > cell phone > electrical signals > highest frequency sounds > laser beam > piezo-electric speakers > piezoelectric materials > radar speed detectors > semiconductor device > skin cancer > sound waves > transistors
Seeing the quantum future... literally
16.01.2017 | University of Sydney
Airborne thermometer to measure Arctic temperatures
11.01.2017 | Moscow Institute of Physics and Technology
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration
"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...
Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.
Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
16.01.2017 | Power and Electrical Engineering
16.01.2017 | Information Technology
16.01.2017 | Power and Electrical Engineering