Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Compact, wavelength-on-demand Quantum Cascade Laser chip offers ultra-sensitive chemical sensing

Abstract:
Engineers from Harvard University have demonstrated a highly versatile, compact and portable Quantum Cascade Laser sensor for the fast detection of a large number of chemicals, ranging from infinitesimal traces of gases to liquids, by broad tuning of the emission wavelength. The potential range of applications is huge, including homeland security, medical diagnostics such as breadth analysis, pollution monitoring, and environmental sensing of the greenhouse gases responsible for global warming.

Compact, wavelength-on-demand Quantum Cascade Laser chip offers ultra-sensitive chemical sensing

CAMBRIDGE, MA | Posted on December 3rd, 2007

The team, which will report its findings in the Dec. 3 issue of Applied Physics Letters, is headed by Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering, and includes graduate student Benjamin Lee, researchers Mikhail Belkin and Jim MacArthur, and undergraduate Ross Audet, all of Harvard's School of Engineering and Applied Sciences. The researchers have also filed for U.S. patents covering this new class of laser chips.

The broad emission spectrum of the Quantum Cascade Laser material, grown by a commercial reactor used for the mass production of semiconductor lasers, is designed using state-of-the-art nanotechnology by controlling the size of nanometric thin quantum wells in the active region. An array of 32 lasers, each designed to emit at a specific wavelength, is then fabricated on a single chip by standard semiconductor processing techniques to have a size of less than one-fourth of a dime. A microcomputer individually fires up and tunes each laser in the array in any desired sequence. This generates a broad and continuously tunable wavelength spectrum that can be used to detect a large number of chemical compounds.

"Our versatile laser spectrometer currently emits any wavelengths between 8.7 and 9.4 microns, in the so-called 'molecular fingerprint region' where most molecules have their telltale absorption features which uniquely identify them," Belkin says. "This ability to design a broad laser spectrum anywhere in the fingerprint region holds the promise of replacing the bulky and large infrared spectrometers currently used for chemical analysis and sensing."

The tunability of the laser chip can be extended up to 10-fold and several widely spaced absorption features can be targeted with the same chip, which will enable the detection in parallel of an extremely large number of trace gases in concentrations of parts per billion in volume. A portable compact spectrometer with this capability would revolutionize chemical sensing.

"These millimeter-size laser chips exploit the inherent enormous wavelength agility of state-of-the-art Quantum Cascade Lasers," says Capasso, who co-invented them in 1994 at Bell Labs. "As a first application we have shown that these widely tunable and extremely compact sensors can measure the spectrum of liquids with the same accuracy and reproducibility of state-of-the-art infrared spectrometers, but with inherently greater spectral resolution."

The team's co-authors are research associates Laurent Diehl and Christian Pfl�gl of Harvard's School of Engineering and Applied Sciences; Doug Oakley, David Chapman, and Antonio Napoleone of MIT Lincoln Laboratory; David Bour, Scott Corzine, and Gloria H�fler, all formerly with Agilent Technologies; and J�r�me Faist of ETH Zurich. The research was supported by DARPA's Optofluidics Center. The authors also acknowledge the support of Harvard's Center for Nanoscale Systems, a member of the National Nanotechnology Infrastructure Network.

####

For more information, please click here

Contacts:
Eliza Grinnell

617-495-2871

Copyright © Harvard University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Nanomedicine

Making nanowires from protein and DNA September 3rd, 2015

Reversible Writing with Light: Self-assembling nanoparticles take their cues from their surroundings September 3rd, 2015

Silk bio-ink could help advance tissue engineering with 3-D printers September 2nd, 2015

Using DNA origami to build nanodevices of the future September 1st, 2015

Sensors

Successful boron-doping of graphene nanoribbon August 27th, 2015

Nanotechnology that will impact the Security & Defense sectors to be discussed at NanoSD2015 conference August 25th, 2015

High Precision, High Stability XYZ Microscope Stages, with Capacitive Feedback August 18th, 2015

Setting ground rules for nanotechnology research: Two new projects set the stage for nanotechnology research to move into Big Data August 18th, 2015

Discoveries

Making nanowires from protein and DNA September 3rd, 2015

Making fuel from light: Argonne research sheds light on photosynthesis and creation of solar fuel September 3rd, 2015

Reversible Writing with Light: Self-assembling nanoparticles take their cues from their surroundings September 3rd, 2015

For 2-D boron, it's all about that base: Rice University theorists show flat boron form would depend on metal substrates September 2nd, 2015

Announcements

Making nanowires from protein and DNA September 3rd, 2015

Making fuel from light: Argonne research sheds light on photosynthesis and creation of solar fuel September 3rd, 2015

Reversible Writing with Light: Self-assembling nanoparticles take their cues from their surroundings September 3rd, 2015

A marine creature's magic trick explained: Crystal structures on the sea sapphire's back appear differently depending on the angle of reflection September 2nd, 2015

Homeland Security

Nanopaper as an optical sensing platform July 23rd, 2015

Iranian Scientists Design Nano Device to Detect Cyanogen Toxic Gas June 23rd, 2015

New sensing tech could help detect diseases, fraudulent art, chemical weapons June 1st, 2015

UCLA nanoscientists are first to model atomic structures of three bacterial nanomachines: Cryo electron microscope enables scientists to explore the frontiers of targeted antibiotics April 21st, 2015

Environment

Reversible Writing with Light: Self-assembling nanoparticles take their cues from their surroundings September 3rd, 2015

RUSNANOPRIZE Directorate Announces New Deadline for Nominations Submission September 11, 2015 September 1st, 2015

Successful boron-doping of graphene nanoribbon August 27th, 2015

Iranian Scientists Utilize Nanomembranes to Purify Wastewater of Olive Oil Plants August 20th, 2015

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic