Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers bend light through waveguides in colloidal crystals

08.01.2008
Researchers at the University of Illinois are the first to achieve optical waveguiding of near-infrared light through features embedded in self-assembled, three-dimensional photonic crystals. Applications for the optically active crystals include low-loss waveguides, low-threshold lasers and on-chip optical circuitry.

Key to the fabrication technique – which uses multi-photon polymerization and a laser scanning confocal microscope – is a self-assembled, colloidal material that exhibits a photonic band gap, said Paul Braun, a University Scholar and professor of materials science and engineering.

In previous work, reported in 2002, Braun’s research group was the first to show that through multi-photon polymerization they could embed a polymer feature inside a silicon dioxide, self-assembled colloidal crystal.

Now, in a paper accepted for publication in Nature Photonics, and posted on the journal’s Web site, Braun and his team demonstrate actual optical activity in waveguides and cavities created in their colloidal crystals.

“Taking our earlier work as a starting point, we built upon recent advances in theory and computation, improvements in materials growth techniques, and better colloidal crystallization capabilities to produce this new photonic material,” said Braun, who also is affiliated with the university’s Beckman Institute, Frederick Seitz Materials Research Laboratory, and Micro and Nanotechnology Laboratory.

To make their optically active devices, the researchers begin by assembling a colloidal crystal of uniform silica spheres that are 900 nanometers in diameter. After removing the solvent, the researchers fill the spaces between the spheres with a photoactive monomer. Then they shine laser light through a microscope and into the crystal, polymerizing the monomer at the desired locations.

Next, they remove the unpolymerized liquid, and then fill the structure with silicon. Finally, they etch away the silica spheres, leaving the desired optical features embedded in a three-dimensional photonic crystal.

“Using spheres 900 nanometers in diameter creates a band gap at 1.5 microns, which is the wavelength used by the telecommunications industry for transmissions through fiber-optical cables,” Braun said. “Creating these waveguides by coupling colloidal assembly and multi-photon polymerization is simpler and less expensive than conventional fabrication techniques, especially for large-area photonic crystals.”

With Braun, co-authors of the paper are Stephanie A. Rinne, a postdoctoral fellow at the Beckman Institute, and Florencio García-Santamaría, a postdoctoral research associate in the department of materials science and engineering.

The work was funded by the U.S. Army Research Office, National Science Foundation and the U.S. Department of Energy.

To reach Paul Braun, call 217-244-7293; e-mail: pbraun@uiuc.edu

James E. Kloeppel | University of Illinois
Further information:
http://www.uiuc.edu

More articles from Physics and Astronomy:

nachricht Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst

nachricht Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>