Featured Research

from universities, journals, and other organizations

Nanophotonics enables new kind of optical spectrometer

Date:
January 28, 2013
Source:
University of Alabama Huntsville
Summary:
By bringing nanophotonics technology to traditional optical spectroscopy, a new kind of optical spectrometer with functions of sensing and spectral measurement has been recently demonstrated.

Dr. Junpeng Guo, UAHuntsville Associate Professor of Electrical Engineering and Optics, and doctoral student Haisheng Leong view the spectra from a new nanoscale photonic device.
Credit: Aaron Sexton / The University of Alabama in Huntsville

By bringing nanophotonics technology to traditional optical spectroscopy, a new kind of optical spectrometer with functions of sensing and spectral measurement has been recently demonstrated by a research team at The University of Alabama in Huntsville.

Dr. Junpeng Guo, Associate Professor of Electrical Engineering and Optics at UAHuntsville, recently created a new nanoscale photonic device called a super nano-grating, with the assistance of his doctoral student, Haisheng Leong. With a fabricated super nano-grating, Dr. Guo's group demonstrated a new kind of optical sensing apparatus called spectrometer sensors.

Traditional optical spectrometers measure the spectra of light. Traditional optical sensors use light to detect the presence of chemicals. A spectrometer sensor is an optical spectrometer and also a chemical sensor because it measures the optical resonance spectrum that is controlled by chemicals bonded on the nanostructure surface. A spectrometer sensor with a super nanoslit metal grating was first published in Optics Letters (vol. 36, 2011) and a spectrometer sensor with a super nanohole metal grating was published recently in Optics Express (vol. 20, 2012).

Nano-gratings are periodic nanostructures with the feature size in the nanometer scale. One nanometer is one millionth of a millimeter, about 1/50,000th of the diameter of a human hair. Because the feature size of nanostructures is less than the wavelength of light, we are not able to see nanostructures with our eyes. However, light can sense nanostructures by strong absorptions at specific wavelengths. This phenomenon is called optical resonance of nanostructures, a fundamental phenomenon in optics.

Optical resonances of nanostructures typically are measured by using optical spectrometers. By creating a super-grating pattern of nanostructures, the UAHuntsville team made super diffraction gratings with nano-grating structures. With the super nano-grating, the resonance of the nanostructure can be measured with a photodetector array. That way, the use of an optical spectrometer is not needed.

The nanostructures, such as nanoholes or nanoslits, are made by using a tightly focused electron beam, a technique called electron-beam lithography. Nanostructure patterns were first drawn with a computer and then sent to the electron-beam lithography machine to control the movement of the tightly focused electron beam to write nanoholes or any other nanostructure patterns in a thin layer of special polymer called e-beam resist.

The e-beam written polymer layer is then developed so the nanostructure patterns are imprinted to the thin polymer layer. The patterned polymer layer works like a mask and an argon ion etching process is used to transfer the pattern from the polymer layer to the thin metal film underneath it. This device was made by Haisheng Leong, a graduate research assistant at UAHuntsville.

The super nano-grating is a super-period nanohole array drilled in a thin gold film on a transparent glass substrate. The thickness of the gold film is 60 nanometers and the size of the nanoholes is about 100 nanometers. The periodic nanoholes in the thin metal film support collective free electron oscillations, referred to as surface plasmons, in the nanostructured metal.

The super nano-gratings have rich physics that needs to be investigated, Dr. Guo said. A paper he wrote and recently published in Applied Physics Letters (vol. 101, 2012) is trying to explain the resonance mode splitting phenomenon observed in the super-nanohole grating. The resonance mode splitting can be utilized to make better sensitivity chemical sensors.

The spectrometer sensors can detect toxins or contaminants in very small quantities. UAHuntsville recently has filed a patent to license the new technology.

"Spectrometer sensors are best suited in applications requiring small size and weight," Dr. Guo said. Such small size and lightweight sensors may be useful for NASA space exploration applications like measuring the chemical makeup on the surface of Mars, he said.


Story Source:

The above story is based on materials provided by University of Alabama Huntsville. Note: Materials may be edited for content and length.


Journal Reference:

  1. Haisheng Leong, Junpeng Guo. A surface plasmon resonance spectrometer using a super-period metal nanohole array. Optics Express, 2012; 20 (19): 21318 DOI: 10.1364/OE.20.021318

Cite This Page:

University of Alabama Huntsville. "Nanophotonics enables new kind of optical spectrometer." ScienceDaily. ScienceDaily, 28 January 2013. <www.sciencedaily.com/releases/2013/01/130128104416.htm>.
University of Alabama Huntsville. (2013, January 28). Nanophotonics enables new kind of optical spectrometer. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2013/01/130128104416.htm
University of Alabama Huntsville. "Nanophotonics enables new kind of optical spectrometer." ScienceDaily. www.sciencedaily.com/releases/2013/01/130128104416.htm (accessed October 1, 2014).

Share This



More Matter & Energy News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

US Police Put Body Cameras to the Test

US Police Put Body Cameras to the Test

AFP (Oct. 1, 2014) Police body cameras are gradually being rolled out across the US, with interest surging after the fatal police shooting in August of an unarmed black teenager. Duration: 02:18 Video provided by AFP
Powered by NewsLook.com
Argentina's Tax Evaders Detected, Hunted Down by Drones

Argentina's Tax Evaders Detected, Hunted Down by Drones

AFP (Sep. 30, 2014) Argentina doesn't only have Lionel Messi the footballer, it has now also acquired "Mesi" the drone system which monitors undeclared mansions, swimming pools and soy fields to curb tax evasion in the country. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Do Video Games Trump Brain Training For Cognitive Boosts?

Do Video Games Trump Brain Training For Cognitive Boosts?

Newsy (Sep. 29, 2014) More and more studies are showing positive benefits to playing video games, but the jury is still out on brain training programs. Video provided by Newsy
Powered by NewsLook.com
CERN Celebrates 60 Years of Science

CERN Celebrates 60 Years of Science

Reuters - Business Video Online (Sep. 29, 2014) CERN, the European Organisation for Nuclear Research, celebrates 60 years of bringing nations together through science. As Joanna Partridge reports from inside the famous science centre it's also planning to turn the Large Hadron Collider particle accelerator back on after an upgrade. Video provided by Reuters
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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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