Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists at the University of the Basque Country succeed in cooling solid material with laser

26.07.2006
A team of researchers at the University of the Basque Country (UPV/EHU) have experimentally demonstrated something that other scientists have been trying to achieve for decades: the cooling of erbium-doped materials with laser light.

Joaquín Fernández, Chair at the Department of Applied Physics at the Bilbao School of Engineering, is leading the team consisting of Professor Rolindes Balda and the Ramón y Cajal researcher, Ángel García Adeva. The findings have been published in Physical Review Letters, the most important magazine in its speciality. Atomic, Molecular, and Optical Physics can be viewed at in digital edition and the printed edition (volume 97, 3rd part) will be published next Friday, 21 July.

Optical cooling is a phenomenon that has sparked great interest over the last couple of decades, particularly in the field of the optical cooling of atomic gases (Bose-Einstein condensed (1)). Cooling solids using laser radiation is much more difficult and, in fact, a very small number of doped materials have been cooled, i.e. materials to which a tiny amount of ions of another element have been added. What has never been achieved to date is the cooling of materials doped with erbium.

Erbium is a metal element belonging to the Rare Earth group (2). Its ions have the property whereby when light of a certain wavelength falls on them, they are capable of amplifying them. This effect is used, for example, to construct light amplifiers in the field of optical telecommunications. To this end, in order to compensate for the weakening of the light signal as it journeys down an optic fibre, the fibre is doped with erbium ions.

In the case of the research undertaken by the UPV/EHU team, the luminous emission of erbium has been used to achieve the cooling of material in which these ions are housed by exciting these ions with laser light. This discovery is not only important for the technical difficulties involved, but also because the optical refrigeration of devices doped with erbium occur at wavelengths and potentials similar to those with which conventional diode lasers operate, thus making these materials ideal candidates for possible applications, unlike other doped materials that have previously been cooled. Amongst these applications are high-power optical fibre lasers, medical diagnostic techniques using laser (optical tomography) and phototherapy. These devices would function by means of dual laser pumping in which the light wavelengths would be used for the laser pumping and the other wavelength (close to the previous one) to produce optical cooling that would counteract the heating produced by the laser action. This heating causes a number of adverse effects. It can alter the properties and even burn the material being worked with.

The main reasons why this team of researchers have managed to obtain a net optical cooling of these erbium-doped materials are the extraordinary optical quality of the materials employed and the fact that the losses due to thermal vibrations in these are very small.

(1) Bose-Einstein condensed is an aggregated state of the material that certain materials have at very low temperatures. It is characterised by the property of a macroscopic amount of the particles of the material pass to the level of minimum energy, known as the fundamental state.

(2) Rare Earths: these are elements known as Lantanides and Actinides and have an electronic structure in which the f orbitals are incomplete. Practically all the rare earth elements have radioactive isotopes.

Garazi Andonegi | alfa
Further information:
http://www.elhuyar.com
http://scitation.aip.org/dbt/dbt.jsp?KEY=PRLTAO&Volume=97&Issue=3

More articles from Physics and Astronomy:

nachricht Gamma rays will reach beyond the limits of light
23.10.2017 | Chalmers University of Technology

nachricht Creation of coherent states in molecules by incoherent electrons
23.10.2017 | Tata Institute of Fundamental Research

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Shrews shrink in winter and regrow in spring

24.10.2017 | Life Sciences

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>