Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

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

UTSA study describes new minimally invasive device to treat cancer and other illnesses: Medicine diffusion capsule could locally treat multiple ailments and diseases over several weeks December 3rd, 2016

Nanobiotix Provides Update on Global Development of Lead Product NBTXR3: Seven clinical trials across the world: More than 2/3 of STS patients recruited in the “act.in.sarc” Phase II/III trial: Phase I/II prostate cancer trial now recruiting in the U.S. November 28th, 2016

From champagne bubbles, dance parties and disease to new nanomaterials: Understanding nucleation of protein filaments might help with Alzheimer's Disease and type 2 Diabetes November 24th, 2016

Nanopolymer-modified protein array can pinpoint hard-to-find cancer biomarker November 17th, 2016

Sensors

Shape matters when light meets atom: Mapping the interaction of a single atom with a single photon may inform design of quantum devices December 4th, 2016

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Tip-assisted chemistry enables chemical reactions at femtoliter scale November 16th, 2016

'Back to the Future' inspires solar nanotech-powered clothing November 15th, 2016

Discoveries

Construction of practical quantum computers radically simplified: Scientists invent ground-breaking new method that puts quantum computers within reach December 5th, 2016

Shape matters when light meets atom: Mapping the interaction of a single atom with a single photon may inform design of quantum devices December 4th, 2016

UTSA study describes new minimally invasive device to treat cancer and other illnesses: Medicine diffusion capsule could locally treat multiple ailments and diseases over several weeks December 3rd, 2016

Novel Electrode Structure Provides New Promise for Lithium-Sulfur Batteries December 3rd, 2016

Announcements

Construction of practical quantum computers radically simplified: Scientists invent ground-breaking new method that puts quantum computers within reach December 5th, 2016

Shape matters when light meets atom: Mapping the interaction of a single atom with a single photon may inform design of quantum devices December 4th, 2016

UTSA study describes new minimally invasive device to treat cancer and other illnesses: Medicine diffusion capsule could locally treat multiple ailments and diseases over several weeks December 3rd, 2016

Novel Electrode Structure Provides New Promise for Lithium-Sulfur Batteries December 3rd, 2016

Homeland Security

Nanosensors on the alert for terrorist threats: Scientists interested in the prospects of gas sensors based on binary metal oxide nanocomposites November 5th, 2016

Nanobionic spinach plants can detect explosives: After sensing dangerous chemicals, the carbon-nanotube-enhanced plants send an alert November 2nd, 2016

Notre Dame researchers find transition point in semiconductor nanomaterials September 6th, 2016

Down to the wire: ONR researchers and new bacteria August 18th, 2016

Environment

Semiconductor-free microelectronics are now possible, thanks to metamaterials November 9th, 2016

First time physicists observed and quantified tiny nanoparticle crossing lipid membrane November 7th, 2016

Nanosensors on the alert for terrorist threats: Scientists interested in the prospects of gas sensors based on binary metal oxide nanocomposites November 5th, 2016

Marsden minds: Amazing projects revealed November 3rd, 2016

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