Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

'Microring' device could aid in future optical technologies

20.10.2011
Researchers at Purdue University and the National Institute of Standards and Technology (NIST) have created a device small enough to fit on a computer chip that converts continuous laser light into numerous ultrashort pulses, a technology that might have applications in more advanced sensors, communications systems and laboratory instruments.

"These pulses repeat at very high rates, corresponding to hundreds of billions of pulses per second," said Andrew Weiner, the Scifres Family Distinguished Professor of Electrical and Computer Engineering.


Researchers have created a tiny "microring resonator," at left, small enough to fit on a computer chip. The device converts continuous laser light into numerous ultrashort pulses, a technology that might have applications in more advanced sensors, communications systems and laboratory instruments. At right is a grooved structure that holds an optical fiber leading into the device. (Birck Nanotechnology Center, Purdue University)

The tiny "microring resonator" is about 80 micrometers, or the width of a human hair, and is fabricated from silicon nitride, which is compatible with silicon material widely used for electronics. Infrared light from a laser enters the chip through a single optical fiber and is directed by a structure called a waveguide into the microring.

The pulses have many segments corresponding to different frequencies, which are called "comb lines" because they resemble teeth on a comb when represented on a graph.

By precisely controlling the frequency combs, researchers hope to create advanced optical sensors that detect and measure hazardous materials or pollutants, ultrasensitive spectroscopy for laboratory research, and optics-based communications systems that transmit greater volumes of information with better quality while increasing bandwidth. The comb technology also has potential for a generation of high-bandwidth electrical signals with possible applications in wireless communications and radar.

The light originates from a continuous-wave laser, also called a single-frequency laser.

"This is a very common type of laser," Weiner said. "The intensity of this type of laser is constant, not pulsed. But in the microring the light is converted into a comb consisting of many frequencies with very nice equal spacing. The microring comb generator may serve as a competing technology to a special type of laser called a mode-locked laser, which generates many frequencies and short pulses. One advantage of the microrings is that they can be very small."

The laser light undergoes "nonlinear interaction" while inside the microring, generating a comb of new frequencies that is emitted out of the device through another optical fiber.

"The nonlinearity is critical to the generation of the comb," said doctoral student Fahmida Ferdous. "With the nonlinearity we obtain a comb of many frequencies, including the original one, and the rest are new ones generated in the microring."

Findings are detailed in a research paper appearing online this month in the journal Nature Photonics. The paper is scheduled for publication in the Dec. 11 issue.

Although other researchers previously have demonstrated the comb-generation technique, the team is the first to process the frequencies using "optical arbitrary waveform technology," pioneered by Purdue researchers led by Weiner. The researchers were able to control the amplitude and phase of each spectral line, learning that there are two types of combs - "highly coherent" and "partially coherent" - opening up new avenues to study the physics of the process.

"In future investigations, the ability to extract the phase of individual comb lines may furnish clues into the physics of the comb-generation process," Ferdous said. "Future work will include efforts to create devices that have the proper frequency for commercial applications."

The silicon-nitride device was fabricated by a team led by Houxun Miao, a researcher at NIST's Center for Nanoscale Science and Technology and the Maryland Nanocenter at the University of Maryland. Some of the work was performed at the Birck Nanotechnology Center in Purdue's Discovery Park, and experiments demonstrating short-pulse generation were performed in Purdue's School of Electrical and Computer Engineering.

The effort at Purdue is funded in part by the National Science Foundation and the Naval Postgraduate School.

Writer: Emil Venere, 765-494-4709, venere@purdue.edu

Sources: Andrew Weiner, 765-494-5574, amw@purdue.edu
Houxun Miao, 301-975-8499, hmiao@nist.gov
Note to Journalists: An electronic copy of the research paper is available by contacting Nature at press@nature.com

Emil Venere | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Physics and Astronomy:

nachricht Cherned up to the maximum
10.07.2020 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Porous graphene ribbons doped with nitrogen for electronics and quantum computing
09.07.2020 | University of Basel

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: The spin state story: Observation of the quantum spin liquid state in novel material

New insight into the spin behavior in an exotic state of matter puts us closer to next-generation spintronic devices

Aside from the deep understanding of the natural world that quantum physics theory offers, scientists worldwide are working tirelessly to bring forth a...

Im Focus: Excitation of robust materials

Kiel physics team observed extremely fast electronic changes in real time in a special material class

In physics, they are currently the subject of intensive research; in electronics, they could enable completely new functions. So-called topological materials...

Im Focus: Electrons in the fast lane

Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.

Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....

Im Focus: The lightest electromagnetic shielding material in the world

Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...

Im Focus: Gentle wall contact – the right scenario for a fusion power plant

Quasi-continuous power exhaust developed as a wall-friendly method on ASDEX Upgrade

A promising operating mode for the plasma of a future power plant has been developed at the ASDEX Upgrade fusion device at Max Planck Institute for Plasma...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

International conference QuApps shows status quo of quantum technology

02.07.2020 | Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

 
Latest News

X-ray scattering shines light on protein folding

10.07.2020 | Life Sciences

Looking at linkers helps to join the dots

10.07.2020 | Materials Sciences

Surprisingly many peculiar long introns found in brain genes

10.07.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>