Broadband Achromatic Metalens Focuses Light Regardless of Polarization
January 21, 2019 | Harvard John A. Paulson School of Engineering and Applied SciencesEstimated reading time: 2 minutes
We live in a polarized world. No, we aren’t talking about politics — we’re talking about light. Much of the light we see and use is partially polarized, meaning its electric field vibrates in specific directions. Lenses designed to work across a range of applications, from phone cameras to microscopes and sensors, need to be able to focus light regardless of its polarization.
Researchers believed that symmetric nanostructures such as circular pillars were essential building blocks to develop photonic devices that are not sensitive to polarization. Now, researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a polarization-insensitive metalens comprised of non-symmetric nanofins that can achromatically focus light across the visible spectrum without aberrations. This flat lens could be used for everything from virtual or augmented reality headsets to microscopy, lithography, sensors, and displays.
“By making this lens polarization insensitive, we have doubled the efficiency of the metalens from previous iterations,” said Wei Ting Chen, a research associate at SEAS and first author of the paper. “This is the first paper that demonstrates both achromatic and polarization insensitive focusing in the visible spectrum.”
The research was led by Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at SEAS, and published in Nature Communications.
In previous research, Capasso, Chen and their team demonstrated that arrays of titanium dioxide nanofins could equally focus wavelengths of light and eliminate chromatic aberration, but those lenses could only focus a circularly polarized light.
“This meant we were essentially discarding half of the incident light which does not possess the right polarization,” said Alexander Zhu, co-author of the study and graduate student at SEAS.
In this latest design, the researchers changed the layout of the nanofins, positioning each pillar so that it is either parallel or perpendicular to its neighbor.
“This new design gives us a lot of freedom to tune the geometrical parameters of the metalens, which allows us to better achieve achromatic focusing across the entire visible range,” said Chen.
“Next we aim to maximize efficiency and make much larger-size achromatic metalenses to bring them into everyday life for a wide range of applications,” said Capasso.
Harvard’s Office of Technology Development has protected the intellectual property relating to this project and is exploring commercialization opportunities.
This research was co-authored by Jared Sisler, and Zameer Bharwani. It was supported by the Air Force Office of Scientific Research and the Defense Advanced Research Projects Agency.
Suggested Items
Gartner Forecasts Worldwide IT Spending to Grow 8% in 2024
04/17/2024 | Gartner, Inc.Worldwide IT spending is expected to total $5.06 trillion in 2024, an increase of 8% from 2023, according to the latest forecast by Gartner, Inc. This is an increase from the previous quarter’s forecast of 6.8% growth and puts worldwide IT spending on track to surpass $8 trillion well before the end of the decade.
Argonne, RIKEN Sign a Memorandum of Understanding in Support of AI for Science
04/16/2024 | BUSINESS WIRELeaders in high performance computing in the U.S. and Japan have signed a memorandum of understanding (MOU) establishing a cooperative relationship in support of artificial intelligence (AI) computing projects.
RAICo Fellowship to Widen Participation Within the Field of Robotics and Artificial Intelligence
04/12/2024 | RAICoWOMEN and those early in their academia career who are passionate about robotics and artificial intelligence are encouraged to apply for a RAICo Fellowship.
Indium to Host Free Webinar on Lead-Free Solder Paste for Automotive Applications
04/09/2024 | Indium CorporationIndium Corporation’s Senior Research Metallurgist, Jie Geng, Ph.D., will conduct a webinar on low-voiding, high-reliability, lead-free solder paste for automotive applications.
SMTA Announces Program for High Reliability: Strategic Technology Advancement Research Forum
04/08/2024 | SMTAThe SMTA announced the finalized program for the High Reliability: Strategic Technology Advancement Research Forum which takes place on May 2, 2024 in Olathe, Kansas, USA. The event, now in its second year, addresses challenges for electronics manufacturers in the high reliability sector.