A marriage of light-manipulation technologies

February 27, 2018

Researchers have, for the first time, integrated two technologies widely used in applications such as optical communications, bio-imaging and Light Detection and Ranging (LIDAR) systems that scan the surroundings of self-driving cars and trucks.

In the collaborative effort between the U.S. Department of Energy's (DOE) Argonne National Laboratory and Harvard University, researchers successfully crafted a metasurface-based lens atop a Micro-Electro-Mechanical System (MEMS) platform. The result is a new infrared light-focusing system that combines the best features of both technologies while reducing the size of the optical system.

Metasurfaces can be structured at the nanoscale to work like lenses. These metalenses were pioneered by Federico Capasso, Harvard's Robert L. Wallace Professor of Applied Physics, and his group at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS). The lenses are rapidly finding applications because they are much thinner and less bulky than existing lenses, and can be made with the same technology used to fabricate computer chips. The MEMSs, meanwhile, are small mechanical devices that consist of tiny, movable mirrors.

"These devices are key today for many technologies. They have become technologically pervasive and have been adopted for everything from activating automobile air bags to the global positioning systems of smart phones," said Daniel Lopez, Nanofabrication and Devices Group Leader at Argonne's Center for Nanoscale Materials, a DOE Office of Science User Facility.

Lopez, Capasso and four co-authors describe how they fabricated and tested their new device in an article in APL Photonics, titled "Dynamic metasurface lens based on MEMS technology." The device measures 900 microns in diameter and 10 microns in thickness (a human hair is approximately 50 microns thick).

The collaboration's ongoing work to further develop novel applications for the two technologies is conducted at Argonne's Center for Nanoscale Materials, SEAS and the Harvard Center for Nanoscale Systems, which is part of the National Nanotechnology Coordinated Infrastructure.

In the technologically merged optical system, MEMS mirrors reflect scanned light, which the metalens then focuses without the need for an additional optical component such as a focusing lens. The challenge that the Argonne/Harvard team overcame was to integrate the two technologies without hurting their performance.

The eventual goal would be to fabricate all components of an optical system -- the MEMS, the light source and the metasurface-based optics -- with the same technology used to manufacture electronics today.

"Then, in principle, optical systems could be made as thin as credit cards," Lopez said.

These lens-on-MEMS devices could advance the LIDAR systems used to guide self-driving cars. Current LIDAR systems, which scan for obstacles in their immediate proximity, are, by contrast, several feet in diameter.

"You need specific, big, bulky lenses, and you need mechanical objects to move them around, which is slow and expensive," said Lopez.

"This first successful integration of metalenses and MEMS, made possible by their highly compatible technologies, will bring high speed and agility to optical systems, as well unprecedented functionalities," said Capasso.
-end-
This work was also supported by the Air Force Office of Scientific Research, the National Science Foundation and the Singapore Agency for Science, Technology and Research's National Science Scholarship.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation's first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America's scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.

The U.S. Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit the Office of Science website.

DOE/Argonne National Laboratory

Related Nanoscale Articles from Brightsurf:

Nanoscale machines convert light into work
Researchers have developed a tiny new machine that converts laser light into work.

Discovery will allow more sophisticated work at nanoscale
The movement of fluids through small capillaries and channels is crucial for processes ranging from blood flow through the brain to power generation and electronic cooling systems, but that movement often stops when the channel is smaller than 10 nanometers.

Valley-Hall nanoscale lasers
Topological photonics allows the creation of new states of light.

Dynamics of DNA replication revealed at the nanoscale
Using super-resolution technology a University of Technology Sydney led team has directly visualised the process of DNA replication in single human cells.

House cleaning on the nanoscale
A team of scientists at Friedrich-Alexander Universität Erlangen-Nürnberg (FAU) has developed a novel mechanical cleaning method for surfaces on the nanoscale.

As electronics shrink to nanoscale, will they still be good as gold?
As circuit interconnects shrink to nanoscale, will the pressure caused by thermal expansion when current flows through wires cause gold to behave more like a liquid than a solid -- making nanoelectronics unreliable?

A joint venture at the nanoscale
Scientists at Argonne National Laboratory report fabricating and testing a superconducting nanowire device applicable to high-speed photon counting.

Bending diamond at the nanoscale
A team of Australian scientists has discovered diamond can be bent and deformed, at the nanoscale at least.

Creating a nanoscale on-off switch for heat
Researchers create a polymer thermal regulator that can quickly transform from a conductor to an insulator, and back again.

Magnetic tuning at the nanoscale
Physicists from the German research center Helmholtz-Zentrum Dresden-Rossendorf (HZDR) are working to produce engineered magnetic nanostructures and to tailor material properties at the nanoscale.

Read More: Nanoscale News and Nanoscale Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.