Compact optical WDs are key in spectral analysis for biosensers small enough to fit on a chip and for integrated circuits for optical information processing.
Georgia Tech researchers have designed a WD able to function at very high resolution in much tighter confines (as small as 64 microns by 100 microns — smaller than a millimeter) by developing a new design for photonic crystals, which are highly periodic structures typically etched in very thin silicon that are designed to control light and have the potential to revolutionize everything from computing to communications. The research had been published in Laser Focus World and Optics Express and was recently presented at the Conference on Lasers and Electro-Optics (CLEO 2006).
“We believe we have developed the most compact WD that has been reported to date,” said Ali Adibi, a professor in Georgia Tech’s School of Electrical and Computer Engineering and the lead researcher on the project. “If you want to have many optical functions on a single micro- or nano-sized chip, you have to be able to practically integrate all those functions in the smallest amount of space possible. Our WD solves many problems associated with combining delicate optical functions in such a small space.”
The Georgia Tech team was able to shrink its WD by combining into one crystal three unique properties of photonics crystals — the superprism effect (separating wavelengths much more finely than a regular prism), negative diffraction or focusing (reversing the expansion of the light beam and focusing it back to its original size after interacting with the material being analyzed) and negative refraction (filtering wanted and unwanted wavelengths).
By combining these effects, Georgia Tech’s WD takes an expanded beam of light and instead of expanding it further as wavelengths are separated, focuses the wavelength into different locations. The structure simultaneously separates wavelengths, focuses wavelengths instead of refracting them and then separates the wavelengths in one structure, solving the problems associated with wavelength interference without adding extra devices to the system.
“This project really demonstrates the importance of dispersion engineering in photonic crystals — and it’s all done by changing the geometry of some holes you etch in the silicon. It’s very simple and it allows you to combine properties into one material that you never could before,” Adibi said.
Despite the more advanced capabilities of the photonic crystals used in Georgia Tech’s WD, they are no more complex or difficult to manufacture than conventional photonic crystals, Adibi added.
The team members created these newly optimized crystals by using a modeling tool they developed two years ago to test the properties of a material much faster than time-consuming conventional numerical methods.
The result is a WD that is less than a millimeter in all dimensions rather than the several centimeters of other currently available WDs. Furthermore, Georgia Tech’s WD can be integrated for several other functionalities on a single chip for signal processing, communications, or sensing and lab on-a-chip applications.
The work was supported by the Air Force Office of Scientific Research (AFOSR, G. Pomrenke) and in part by the National Science Foundation (NSF) and David and Lucile Packard Foundation.
The Georgia Institute of Technology is one of the nation's premiere research universities. Ranked ninth among U.S. News & World Report's top public universities, Georgia Tech educates more than 17,000 students every year through its Colleges of Architecture, Computing, Engineering, Liberal Arts, Management and Sciences. Tech maintains a diverse campus and is among the nation's top producers of women and African-American engineers. The Institute offers research opportunities to both undergraduate and graduate students and is home to more than 100 interdisciplinary units plus the Georgia Tech Research Institute. During the 2004-2005 academic year, Georgia Tech reached $357 million in new research award funding. The Institute also maintains an international presence with campuses in France and Singapore and partnerships throughout the world.
Megan McRainey | EurekAlert!
Observations of nearby supernova and associated jet cocoon provide new insights on gamma-ray bursts
18.01.2019 | George Washington University
A new twist on a mesmerizing story
17.01.2019 | ETH Zurich Department of Physics
The scientific and political community alike stress the importance of German Antarctic research
Joint Press Release from the BMBF and AWI
The Antarctic is a frigid continent south of the Antarctic Circle, where researchers are the only inhabitants. Despite the hostile conditions, here the Alfred...
World first experiments on sensor that may revolutionise everything from medical devices to unmanned vehicles
The new sensor - capable of detecting vibrations of living cells - may revolutionise everything from medical devices to unmanned vehicles.
Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.
In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...
Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.
It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:
The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.
One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...
16.01.2019 | Event News
14.01.2019 | Event News
12.12.2018 | Event News
18.01.2019 | Materials Sciences
18.01.2019 | Life Sciences
18.01.2019 | Health and Medicine