Nav: Home

New metasurface design can control optical fields in three dimensions

October 04, 2019

A team led by scientists at the University of Washington has designed and tested a 3D-printed metamaterial that can manipulate light with nanoscale precision. As they report in a paper published Oct. 4 in the journal Science Advances, their designed optical element focuses light to discrete points in a 3D helical pattern.

The team's design principles and experimental findings demonstrate that it is possible to model and construct metamaterial devices that can precisely manipulate optical fields with high spatial resolution in three dimensions. Though the team chose a helical pattern -- a spiral helix -- for their optical element to focus light, their approach could be used to design optical elements that control and focus light in other patterns.

Devices with this level of precision control over light could be used not only to miniaturize today's optical elements, such as lenses or retroreflectors, but also to realize new varieties. In addition, designing optical fields in three dimensions could enable creation of ultra-compact depth sensors for autonomous transportation, as well as optical elements for displays and sensors in virtual- or augmented-reality headsets.

"This reported device really has no classical analog in refractive optics -- the optics that we encounter in our day-to-day life," said corresponding author Arka Majumdar, a UW assistant professor of electrical and computer engineering and physics, and faculty member at the UW Institute for Nano-Engineered Systems and the Institute for Molecular & Engineering Sciences. "No one has really made a device like this before with this set of capabilities."

The team, which includes researchers at the Air Force Research Laboratory and the University of Dayton Research Institute, took a lesser-used approach in the optical metamaterials field to design the optical element: inverse design. Using inverse design, they started with the type of optical field profile they wanted to generate -- eight focused points of light in a helical pattern -- and designed a metamaterial surface that would create that pattern.

"We do not always intuitively know the appropriate structure of an optical element given a specific functionality," said Majumdar. "This is where the inverse design comes in: You let the algorithm design the optics."

While this approach seems straightforward and avoids the drawbacks of trial-and-error design methods, inverse design isn't widely used for optically active large-area metamaterials because it requires a large number of simulations, making inverse design computationally intensive.

Here, the team avoided this pitfall thanks to an insight by Alan Zhan, lead author on the paper, who recently graduated the UW with a doctoral degree in physics. Zhan realized that the team could use Mie scattering theory to design the optical element. Mie scattering describes how light waves of a particular wavelength are scattered by spheres or cylinders that are similar in size to the optical wavelength. Mie scattering theory explains how metallic nanoparticles in stained glass can give certain church windows their bold colors, and how other stained glass artifacts change color in different wavelengths of light, according to Zhan.

"Our implementation of Mie scattering theory is specific to certain shapes -- spheres-- which meant we had to incorporate those shapes into the design of the optical element," said Zhan. "But, relying on Mie scattering theory significantly simplified the design and simulation process because we could make very specific, very precise calculations about the properties of light when it interacts with the optical element."

Their approach could be employed to include different geometries such as cylinders and ellipsoids.

The optical element the team designed is essentially a surface covered in thousands of tiny spheres of different sizes, arranged in a periodic square lattice. Using spheres simplified the design, and the team used a commercially available 3D printer to fabricate two prototype optical elements -- the larger of the two with sides just 0.02 centimeters long -- at the Washington Nanofabrication Facility on the UW campus. The optical elements were 3D-printed out of an ultraviolet epoxy on glass surfaces. One element was designed to focus light at 1,550 nanometers, the other at 3,000 nanometers.

The researchers visualized the optical elements under a microscope to see how well they performed as designed -- focusing light of either 1,550 or 3,000 nanometers at eight specific points along a 3D helical pattern. Under the microscope, most focused points of light were at the positions predicted by the team's theoretical simulations. For example, for the 1,550-nanometer wavelength device, six of eight focal points were in the predicted position. The remaining two showed only minor deviations.

With the high performance of their prototypes, the team would like to improve the design process to reduce background levels of light and improve the accuracy of the placement of the focal points, and to incorporate other design elements compatible with Mie scattering theory.

"Now that we've shown the basic design principles work, there are lots of directions we can go with this level of precision in fabrication," said Majumdar.

One particularly promising direction is to progress beyond a single-surface to create a true-volume, 3D metamaterial.

"3D-printing allows us to create a stack of these surfaces, which was not possible before," said Majumdar.
Co-authors are Ricky Gibson with the Air Force Research Laboratory and the University of Dayton Research Institute; Evan Smith and Joshua Hendrickson with the Air Force Research Laboratory; and James Whitehead, a UW doctoral student in the Department of Electrical and Computer Engineering. The research was funded by the National Science Foundation, the Air Force Office of Scientific Research, Samsung, the UW Reality Lab, Facebook, Google and Huawei.

For more information, contact Majumdar at

Grant numbers: 1825308, FA9550-15RYCOR159

Link to embargoed release, images and caption/credit information:

Manuscript information:

Title: "Controlling three-dimensional optical fields via inverse Mie scattering"
Authors: Zhan A, Gibson R, Whitehead J, Smith E, Hendrickson JR, Majumdar A
Journal: Science Advances
DOI: 10.1126/sciadv.aax4769

To request an advance copy of the manuscript, please contact the AAAS Office of Public Programs at +1-202-326-6440 or

University of Washington

Related Physics Articles:

Challenges and opportunities for women in physics
Women in the United States hold fewer than 25% of bachelor's degrees, 20% of doctoral degrees and 19% of faculty positions in physics.
Indeterminist physics for an open world
Classical physics is characterized by the equations describing the world.
Leptons help in tracking new physics
Electrons with 'colleagues' -- other leptons - are one of many products of collisions observed in the LHCb experiment at the Large Hadron Collider.
Has physics ever been deterministic?
Researchers from the Austrian Academy of Sciences, the University of Vienna and the University of Geneva, have proposed a new interpretation of classical physics without real numbers.
Twisted physics
A new study in the journal Nature shows that superconductivity in bilayer graphene can be turned on or off with a small voltage change, increasing its usefulness for electronic devices.
Physics vs. asthma
A research team from the MIPT Center for Molecular Mechanisms of Aging and Age-Related Diseases has collaborated with colleagues from the U.S., Canada, France, and Germany to determine the spatial structure of the CysLT1 receptor.
2D topological physics from shaking a 1D wire
Published in Physical Review X, this new study propose a realistic scheme to observe a 'cold-atomic quantum Hall effect.'
Helping physics teachers who don't know physics
A shortage of high school physics teachers has led to teachers with little-to-no training taking over physics classrooms, reports show.
Physics at the edge
In 2005, condensed matter physicists Charles Kane and Eugene Mele considered the fate of graphene at low temperatures.
Using physics to print living tissue
3D printers can be used to make a variety of useful objects by building up a shape, layer by layer.
More Physics News and Physics Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

TED Radio Wow-er
School's out, but many kids–and their parents–are still stuck at home. Let's keep learning together. Special guest Guy Raz joins Manoush for an hour packed with TED science lessons for everyone.
Now Playing: Science for the People

#565 The Great Wide Indoors
We're all spending a bit more time indoors this summer than we probably figured. But did you ever stop to think about why the places we live and work as designed the way they are? And how they could be designed better? We're talking with Emily Anthes about her new book "The Great Indoors: The Surprising Science of how Buildings Shape our Behavior, Health and Happiness".
Now Playing: Radiolab

The Third. A TED Talk.
Jad gives a TED talk about his life as a journalist and how Radiolab has evolved over the years. Here's how TED described it:How do you end a story? Host of Radiolab Jad Abumrad tells how his search for an answer led him home to the mountains of Tennessee, where he met an unexpected teacher: Dolly Parton.Jad Nicholas Abumrad is a Lebanese-American radio host, composer and producer. He is the founder of the syndicated public radio program Radiolab, which is broadcast on over 600 radio stations nationwide and is downloaded more than 120 million times a year as a podcast. He also created More Perfect, a podcast that tells the stories behind the Supreme Court's most famous decisions. And most recently, Dolly Parton's America, a nine-episode podcast exploring the life and times of the iconic country music star. Abumrad has received three Peabody Awards and was named a MacArthur Fellow in 2011.