Featured Research

from universities, journals, and other organizations

Laser physics turned upside down: New way to generate tunable wavelengths using quantum-dot technology

Date:
April 17, 2010
Source:
Technische Universität Darmstadt
Summary:
Physicists in Germany have developed a new method for generating tunable wavelengths, as well as more easily switching back and forth between two wavelengths, employing quantum-dot lasers. The finding could have a number of applications in biomedicine and nanosurgery.

Researchers led by Professor Wolfgang Elsaesser are providing new insights into laser physics.
Credit: Photo by Katrin Binner

Researchers at the Technische Universität Darmstadt have found a new method for generating tunable wavelengths, as well as more easily switching back and forth between two wavelengths, employing quantum-dot lasers. Prospective application fields are biomedicine and nanosurgery.

Darmstadt physicists have discovered an effect that turns the physics of semiconductor lasers "upside down." Laser action in semiconductor lasers usually starts off with emission of photons corresponding to transitions originating from the lowest energy level. Emission of high energetic, i.e., short-wavelength, photons does not normally commence until the pumping current has been increased to well above the lasing threshold.

Under the EU's "FAST-DOT" project, researchers from the Semiconductor Optics Group at the Technische Universität Darmstadt's Institute for Applied Physics headed by Prof. Dr. Wolfgang Elsäßer have recently discovered that, under some circumstances, quantum-dot lasers do emit first short-wavelength photons and then long-wavelength photons. Elsäßer explained that "this inverted hierarchy of emission states that we are the first to discover effectively allows generating intentionally custom-tailored wave­lengths covering a wavelength range of interest in many applications. Furthermore, the method not only allows switching back and forth between two wavelengths and but also exploiting beneficially effects occurring in the laser systems involved for improving pulse parameters."

Following up on that work, the Darmstadt researchers engaged in the "FAST-DOT" project plan to explore applications of the easier means for switching between wave­lengths, whose underlying physics they have discovered.

Medical applications of nanostructured quantum-dot lasers

Quantum-dot lasers operable at high pulse-repetition rates are capable of reaching pulse energies that will allow modifying living cells, e.g., making accurately controlled incisions in cell structures, while minimizing the attendant effects on cellular environments. Summarizing their capabilities, Elsäßer stated that, "They may be employed as high-precision scalpels, with which cell structures may be parted in controlled manners."

In addition, certain cell organelles might be deactivated or individual intracel­lular or extracellular molecules activated, which would open up unforeseen opportunities in molecular surgery, which allows making incisions two-thousand times finer than a human hair. In the future, these quantum dot lasers might allow destroying cancer cells very specifically or applying them simultaneously either for corneal surgery or diagnostics.


Story Source:

The above story is based on materials provided by Technische Universität Darmstadt. Note: Materials may be edited for content and length.


Cite This Page:

Technische Universität Darmstadt. "Laser physics turned upside down: New way to generate tunable wavelengths using quantum-dot technology." ScienceDaily. ScienceDaily, 17 April 2010. <www.sciencedaily.com/releases/2010/04/100414083537.htm>.
Technische Universität Darmstadt. (2010, April 17). Laser physics turned upside down: New way to generate tunable wavelengths using quantum-dot technology. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2010/04/100414083537.htm
Technische Universität Darmstadt. "Laser physics turned upside down: New way to generate tunable wavelengths using quantum-dot technology." ScienceDaily. www.sciencedaily.com/releases/2010/04/100414083537.htm (accessed September 21, 2014).

Share This



More Matter & Energy News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

What This MIT Sensor Could Mean For The Future Of Robotics

What This MIT Sensor Could Mean For The Future Of Robotics

Newsy (Sep. 20, 2014) — MIT researchers developed a light-based sensor that gives robots 100 times the sensitivity of a human finger, allowing for "unprecedented dexterity." Video provided by Newsy
Powered by NewsLook.com
MIT BioSuit A New Take On Traditional Spacesuits

MIT BioSuit A New Take On Traditional Spacesuits

Newsy (Sep. 19, 2014) — The MIT BioSuit could be an alternative to big, bulky traditional spacesuits, but the concept needs some work. Video provided by Newsy
Powered by NewsLook.com
New Music With Recycled Instruments at Colombia Fest

New Music With Recycled Instruments at Colombia Fest

AFP (Sep. 19, 2014) — Jars, bottles, caps and even a pizza box, recovered from the trash, were the elements used by four musical groups at the "RSFEST2014 Sonorities Recycling Festival", in Colombian city of Cali. Duration: 00:49 Video provided by AFP
Powered by NewsLook.com
Virtual Reality Headsets Unveiled at Tokyo Game Show

Virtual Reality Headsets Unveiled at Tokyo Game Show

AFP (Sep. 18, 2014) — Several companies unveiled virtual reality headsets at the Tokyo Game Show, Asia's largest digital entertainment exhibition. Duration: 00:48 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins