Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Columbia engineers build smallest integrated Kerr frequency comb generator

09.10.2018

Low-power chip unites lasers and frequency combs for the first time and can be powered by an AAA battery, opening the door to portable devices for a wide range of applications from spectroscopy to optical communications to LIDAR

Optical frequency combs can enable ultrafast processes in physics, biology, and chemistry, as well as improve communication and navigation, medical testing, and security. The Nobel Prize in Physics 2005 was awarded to the developers of laser-based precision spectroscopy, including the optical frequency comb technique, and microresonator combs have become an intense focus of research over the past decade.


Illustration showing an array of microring resonators on a chip converting laser light into frequency combs.

Credit: Brian Stern/Columbia Engineering

A major challenge has been how to make such comb sources smaller and more robust and portable. In the past 10 years, major advances have been made in the use of monolithic, chip-based microresonators to produce such combs. While the microresonators generating the frequency combs are tiny--smaller than a human hair--they have always relied on external lasers that are often much larger, expensive, and power-hungry.

Researchers at Columbia Engineering announced today in Nature that they have built a Kerr frequency comb generator that, for the first time, integrates the laser together with the microresonator, significantly shrinking the system's size and power requirements. They designed the laser so that half of the laser cavity is based on a semiconductor waveguide section with high optical gain, while the other half is based on waveguides, made of silicon nitride, a very low-loss material. Their results showed that they no longer need to connect separate devices in the lab using fiber--they can now integrate it all on photonic chips that are compact and energy efficient.

The team knew that the lower the optical loss in the silicon nitride waveguides, the lower the laser power needed to generate a frequency comb. "Figuring out how to eliminate most of the loss in silicon nitride took years of work from many students in our group," says Michal Lipson, Eugene Higgins Professor of Electrical Engineering, professor of applied physics, and co-leader of the team. "Last year we demonstrated that we could reproducibly achieve very transparent low-loss waveguides. This work was key to reducing the power needed to generate a frequency comb on-chip, which we show in this new paper."

Microresonators are typically small, round disks or rings made of silicon, glass, or silicon nitride. Bending a waveguide into the shape of a ring creates an optical cavity in which light circulates many times, leading to a large buildup of power. If the ring is properly designed, a single-frequency pump laser input can generate an entire frequency comb in the ring. The Columbia Engineering team made another key innovation: in microresonators with extremely low loss like theirs, light circulates and builds up so much intensity that they could see a strong reflection coming back from the ring.

"We actually placed the microresonator directly at the edge of the laser cavity so that this reflection made the ring act just like one of the laser's mirrors--the reflection helped to keep the laser perfectly aligned," says Brian Stern, the study's lead author who conducted the work as a doctoral student in Lipson's group. "So, rather than using a standard external laser to pump the frequency comb in a separate microresonator, we now have the freedom to design the laser so that we can make the laser and resonator interact in new ways."

All of the optics fit in a millimeter-scale area and the researchers say that their novel device is so efficient that even a common AAA battery can power it. "Its compact size and low power requirements open the door to developing portable frequency comb devices," says Alexander Gaeta, Rickey Professor of Applied Physics and of Materials Science and team co-leader. "They could be used for ultra-precise optical clocks, for laser radar /LIDAR in autonomous cars, or for spectroscopy to sense biological or environmental markers. We are bringing frequency combs from table-top lab experiments closer to portable, or even wearable, devices."

The researchers plan to apply such devices in various configurations for high precision measurements and sensing. In addition, they will extend these designs for operation in other wavelength ranges, such as the mid-infrared where sensing of chemical and biological agents is highly effective. In cooperation with Columbia Technology Ventures, the team has a provisional patent application and is exploring commercialization of this device.

###

About the Study

The study is titled "Battery-operated integrated frequency comb generator."

Authors are: Brian Stern and Xingchen Ji (School of Electrical and Computer Engineering, Cornell University, and Department of Electrical Engineering, Columbia University); Yoshitomo Okawachi and Alexander L. Gaeta (Department of Applied Physics and Applied Mathematics, Columbia University), and Michal Lipson (Department of Electrical Engineering, Columbia University)

This work was supported by AFRL program award number FA8650-17-P-1085; the ARPA-E ENLITENED program (DE-AR0000843); Defense Advanced Research Projects Agency (DARPA) under the Microsystems Technology Office Direct On-Chip Digital Optical Synthesizer (DODOS) program (N66001-16-1-4052) and the Modular Optical Aperture Building Blocks (MOABB) program (HR0011-16-C-0107); the STTR program (N00014-16-P-30); and Air Force Office of Scientific Research (AFOSR) (FA9550-15-1-0303). This work was performed in part at Cornell NanoScale Facility, an NNCI member supported by NSF Grant ECCS-1542081.

The authors declare no financial or other conflicts of interest. The authors have filed a patent with Columbia Technology Ventures,

LINKS:

Paper: http://dx.doi.org/10.1038/s41586-018-0598-9/
DOI: 10.1038/s41586-018-0598-9 https://www.nobelprize.org/prizes/physics/2005/9800-the-nobel-prize-in-physics-2005-2005-3/
http://engineering.columbia.edu/
https://engineering.columbia.edu/faculty/michal-lipson
http://apam.columbia.edu/
https://www.osapublishing.org/optica/abstract.cfm?uri=optica-4-6-619
http://apam.columbia.edu/alexander-l-gaeta
http://techventures.columbia.edu/

Columbia Engineering

Columbia Engineering, based in New York City, is one of the top engineering schools in the U.S. and one of the oldest in the nation. Also known as The Fu Foundation School of Engineering and Applied Science, the School expands knowledge and advances technology through the pioneering research of its more than 250 faculty, while educating undergraduate and graduate students in a collaborative environment to become leaders informed by a firm foundation in engineering. The School's faculty are at the center of the University's cross-disciplinary research, contributing to the Data Science Institute, Earth Institute, Zuckerman Mind Brain Behavior Institute, Precision Medicine Initiative, and the Columbia Nano Initiative. Guided by its strategic vision, "Columbia Engineering for Humanity," the School aims to translate ideas into innovations that foster a sustainable, healthy, secure, connected, and creative humanity.

Holly Evarts | EurekAlert!
Further information:
http://dx.doi.org/10.1038/s41586-018-0598-9

More articles from Physics and Astronomy:

nachricht Explained: Why water droplets 'bounce off the walls'
27.02.2020 | University of Warwick

nachricht Scientists 'film' a quantum measurement
26.02.2020 | Stockholm University

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: High-pressure scientists in Bayreuth discover promising material for information technology

Researchers at the University of Bayreuth have discovered an unusual material: When cooled down to two degrees Celsius, its crystal structure and electronic properties change abruptly and significantly. In this new state, the distances between iron atoms can be tailored with the help of light beams. This opens up intriguing possibilities for application in the field of information technology. The scientists have presented their discovery in the journal "Angewandte Chemie - International Edition". The new findings are the result of close cooperation with partnering facilities in Augsburg, Dresden, Hamburg, and Moscow.

The material is an unusual form of iron oxide with the formula Fe₅O₆. The researchers produced it at a pressure of 15 gigapascals in a high-pressure laboratory...

Im Focus: From China to the South Pole: Joining forces to solve the neutrino mass puzzle

Study by Mainz physicists indicates that the next generation of neutrino experiments may well find the answer to one of the most pressing issues in neutrino physics

Among the most exciting challenges in modern physics is the identification of the neutrino mass ordering. Physicists from the Cluster of Excellence PRISMA+ at...

Im Focus: Therapies without drugs

Fraunhofer researchers are investigating the potential of microimplants to stimulate nerve cells and treat chronic conditions like asthma, diabetes, or Parkinson’s disease. Find out what makes this form of treatment so appealing and which challenges the researchers still have to master.

A study by the Robert Koch Institute has found that one in four women will suffer from weak bladders at some point in their lives. Treatments of this condition...

Im Focus: A step towards controlling spin-dependent petahertz electronics by material defects

The operational speed of semiconductors in various electronic and optoelectronic devices is limited to several gigahertz (a billion oscillations per second). This constrains the upper limit of the operational speed of computing. Now researchers from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, and the Indian Institute of Technology in Bombay have explained how these processes can be sped up through the use of light waves and defected solid materials.

Light waves perform several hundred trillion oscillations per second. Hence, it is natural to envision employing light oscillations to drive the electronic...

Im Focus: Freiburg researcher investigate the origins of surface texture

Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.

Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

70th Lindau Nobel Laureate Meeting: Around 70 Laureates set to meet with young scientists from approx. 100 countries

12.02.2020 | Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

 
Latest News

Bacteria loop-the-loop

27.02.2020 | Life Sciences

Project on microorganisms: Saci, the bio-factory

27.02.2020 | Life Sciences

New method converts carbon dioxide to methane at low temperatures

27.02.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>