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!
Meteoritic stardust unlocks timing of supernova dust formation
19.01.2018 | Carnegie Institution for Science
Artificial agent designs quantum experiments
19.01.2018 | Universität Innsbruck
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy