1
|
Siegel J, Kim S, Fortman M, Wan C, Kats MA, Hon PWC, Sweatlock L, Jang MS, Brar VW. Electrostatic steering of thermal emission with active metasurface control of delocalized modes. Nat Commun 2024; 15:3376. [PMID: 38643246 PMCID: PMC11032313 DOI: 10.1038/s41467-024-47229-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 03/25/2024] [Indexed: 04/22/2024] Open
Abstract
We theoretically describe and experimentally demonstrate a graphene-integrated metasurface structure that enables electrically-tunable directional control of thermal emission. This device consists of a dielectric spacer that acts as a Fabry-Perot resonator supporting long-range delocalized modes bounded on one side by an electrostatically tunable metal-graphene metasurface. By varying the Fermi level of the graphene, the accumulated phase of the Fabry-Perot mode is shifted, which changes the direction of absorption and emission at a fixed frequency. We directly measure the frequency- and angle-dependent emissivity of the thermal emission from a fabricated device heated to 250 °C. Our results show that electrostatic control allows the thermal emission at 6.61 μm to be continuously steered over 16°, with a peak emissivity maintained above 0.9. We analyze the dynamic behavior of the thermal emission steerer theoretically using a Fano interference model, and use the model to design optimized thermal steerer structures.
Collapse
Affiliation(s)
- Joel Siegel
- Department of Physics, University of Wisconsin-Madison, Madison, WI, USA
| | - Shinho Kim
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Margaret Fortman
- Department of Physics, University of Wisconsin-Madison, Madison, WI, USA
| | - Chenghao Wan
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Mikhail A Kats
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | | | | | - Min Seok Jang
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea.
| | - Victor Watson Brar
- Department of Physics, University of Wisconsin-Madison, Madison, WI, USA.
| |
Collapse
|
2
|
Huang L, Han Z, Wirth-Singh A, Saragadam V, Mukherjee S, Fröch JE, Tanguy QAA, Rollag J, Gibson R, Hendrickson JR, Hon PWC, Kigner O, Coppens Z, Böhringer KF, Veeraraghavan A, Majumdar A. Broadband thermal imaging using meta-optics. Nat Commun 2024; 15:1662. [PMID: 38395983 PMCID: PMC10891089 DOI: 10.1038/s41467-024-45904-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
Subwavelength diffractive optics known as meta-optics have demonstrated the potential to significantly miniaturize imaging systems. However, despite impressive demonstrations, most meta-optical imaging systems suffer from strong chromatic aberrations, limiting their utilities. Here, we employ inverse-design to create broadband meta-optics operating in the long-wave infrared (LWIR) regime (8-12 μm). Via a deep-learning assisted multi-scale differentiable framework that links meta-atoms to the phase, we maximize the wavelength-averaged volume under the modulation transfer function (MTF) surface of the meta-optics. Our design framework merges local phase-engineering via meta-atoms and global engineering of the scatterer within a single pipeline. We corroborate our design by fabricating and experimentally characterizing all-silicon LWIR meta-optics. Our engineered meta-optic is complemented by a simple computational backend that dramatically improves the quality of the captured image. We experimentally demonstrate a six-fold improvement of the wavelength-averaged Strehl ratio over the traditional hyperboloid metalens for broadband imaging.
Collapse
Affiliation(s)
- Luocheng Huang
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, USA
| | - Zheyi Han
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, USA
| | - Anna Wirth-Singh
- Department of Physics, University of Washington, Seattle, WA, USA
| | | | - Saswata Mukherjee
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, USA
| | - Johannes E Fröch
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, USA
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Quentin A A Tanguy
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, USA
| | - Joshua Rollag
- KBR, Inc., Beavercreek, OH, USA
- Sensors Directorate, Air Force Research Laboratory, Wright-Patterson AFB, OH, USA
| | - Ricky Gibson
- Sensors Directorate, Air Force Research Laboratory, Wright-Patterson AFB, OH, USA
| | - Joshua R Hendrickson
- Sensors Directorate, Air Force Research Laboratory, Wright-Patterson AFB, OH, USA
| | - Philip W C Hon
- NG Next, Northrop Grumman Corporation, Redondo Beach, CA, USA
| | - Orrin Kigner
- NG Next, Northrop Grumman Corporation, Redondo Beach, CA, USA
| | | | - Karl F Böhringer
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, USA
- Institute for Nano-Engineered Systems, University of Washington, Seattle, WA, USA
| | | | - Arka Majumdar
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, USA.
- Department of Physics, University of Washington, Seattle, WA, USA.
| |
Collapse
|
3
|
Roberts G, Ballew C, Zheng T, Garcia JC, Camayd-Muñoz S, Hon PWC, Faraon A. 3D-patterned inverse-designed mid-infrared metaoptics. Nat Commun 2023; 14:2768. [PMID: 37179338 PMCID: PMC10183040 DOI: 10.1038/s41467-023-38258-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 04/14/2023] [Indexed: 05/15/2023] Open
Abstract
Modern imaging systems can be enhanced in efficiency, compactness, and application through the introduction of multilayer nanopatterned structures for manipulation of light based on its fundamental properties. High transmission multispectral imaging is elusive due to the commonplace use of filter arrays which discard most of the incident light. Further, given the challenges of miniaturizing optical systems, most cameras do not leverage the wealth of information in polarization and spatial degrees of freedom. Optical metamaterials can respond to these electromagnetic properties but have been explored primarily in single-layer geometries, limiting their performance and multifunctional capacity. Here we use advanced two-photon lithography to realize multilayer scattering structures that achieve highly nontrivial optical transformations intended to process light just before it reaches a focal plane array. Computationally optimized multispectral and polarimetric sorting devices are fabricated with submicron feature sizes and experimentally validated in the mid-infrared. A final structure shown in simulation redirects light based on its angular momentum. These devices demonstrate that with precise 3-dimensional nanopatterning, one can directly modify the scattering properties of a sensor array to create advanced imaging systems.
Collapse
Affiliation(s)
- Gregory Roberts
- Kavli Nanoscience Institute and Thomas J. Watson Sr. Laboratory of Applied Physics, California Institute of Technology, 1200 E California Blvd, Pasadena, 91125, CA, USA
| | - Conner Ballew
- Kavli Nanoscience Institute and Thomas J. Watson Sr. Laboratory of Applied Physics, California Institute of Technology, 1200 E California Blvd, Pasadena, 91125, CA, USA
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr, Pasadena, 91109, CA, USA
| | - Tianzhe Zheng
- Kavli Nanoscience Institute and Thomas J. Watson Sr. Laboratory of Applied Physics, California Institute of Technology, 1200 E California Blvd, Pasadena, 91125, CA, USA
| | - Juan C Garcia
- NG Next, Northrop Grumman Corporation, 1 Space Park Drive, Redondo Beach, 90278, CA, USA
| | - Sarah Camayd-Muñoz
- Kavli Nanoscience Institute and Thomas J. Watson Sr. Laboratory of Applied Physics, California Institute of Technology, 1200 E California Blvd, Pasadena, 91125, CA, USA
- Applied Physics Laboratory, The Johns Hopkins University, 11100 Johns Hopkins Road, Laurel, 20723, MD, USA
| | - Philip W C Hon
- NG Next, Northrop Grumman Corporation, 1 Space Park Drive, Redondo Beach, 90278, CA, USA
| | - Andrei Faraon
- Kavli Nanoscience Institute and Thomas J. Watson Sr. Laboratory of Applied Physics, California Institute of Technology, 1200 E California Blvd, Pasadena, 91125, CA, USA.
| |
Collapse
|
4
|
Kigner O, Meem M, Baker B, Banerji S, Hon PWC, Sensale-Rodriguez B, Menon R. Monolithic all-silicon flat lens for broadband LWIR imaging. Opt Lett 2021; 46:4069-4071. [PMID: 34388813 DOI: 10.1364/ol.426384] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 07/18/2021] [Indexed: 06/13/2023]
Abstract
We designed, fabricated, and characterized a flat multi-level diffractive lens comprised of only silicon with diameter=15.2mm, focal length=19mm, numerical aperture of 0.371, and operating over the long-wave infrared (LWIR) spectrum=8µm to 14 µm. We experimentally demonstrated a field of view of 46°, depth of focus >5mm, and wavelength-averaged Strehl ratio of 0.46. All of these metrics were comparable to those of a conventional refractive lens. The active device thickness is only 8 µm, and its weight (including the silicon substrate) is less than 0.2 g.
Collapse
|
5
|
Meem M, Majumder A, Banerji S, Garcia JC, Kigner OB, Hon PWC, Sensale-Rodriguez B, Menon R. Imaging from the visible to the longwave infrared wavelengths via an inverse-designed flat lens. Opt Express 2021; 29:20715-20723. [PMID: 34266154 DOI: 10.1364/oe.423764] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
It is generally assumed that correcting chromatic aberrations in imaging requires multiple optical elements. Here, we show that by allowing the phase in the image plane to be a free parameter, it is possible to correct chromatic variation of focal length over an extremely large bandwidth, from the visible (Vis) to the longwave infrared (LWIR) wavelengths using a single diffractive surface, i.e., a flat lens. Specifically, we designed, fabricated and characterized a flat, multi-level diffractive lens (MDL) with a thickness of ≤ 10µm, diameter of ∼1mm, and focal length of 18mm, which was constant over the operating bandwidth of λ=0.45µm (blue) to 15µm (LWIR). We experimentally characterized the point-spread functions, aberrations and imaging performance of cameras comprised of this MDL and appropriate image sensors for λ=0.45μm to 11μm. We further show using simulations that such extreme achromatic MDLs can be achieved even at high numerical apertures (NA=0.81). By drastically increasing the operating bandwidth and eliminating several refractive lenses, our approach enables thinner, lighter and simpler imaging systems.
Collapse
|
6
|
Morsy AM, Barako MT, Jankovic V, Wheeler VD, Knight MW, Papadakis GT, Sweatlock LA, Hon PWC, Povinelli ML. Experimental demonstration of dynamic thermal regulation using vanadium dioxide thin films. Sci Rep 2020; 10:13964. [PMID: 32811889 PMCID: PMC7435187 DOI: 10.1038/s41598-020-70931-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 08/06/2020] [Indexed: 11/09/2022] Open
Abstract
We present an experimental demonstration of passive, dynamic thermal regulation in a solid-state system with temperature-dependent thermal emissivity switching. We achieve this effect using a multilayered device, comprised of a vanadium dioxide (VO2) thin film on a silicon substrate with a gold back reflector. We experimentally characterize the optical properties of the VO2 film and use the results to optimize device design. Using a calibrated, transient calorimetry experiment we directly measure the temperature fluctuations arising from a time-varying heat load. Under laboratory conditions, we find that the device regulates temperature better than a constant emissivity sample. We use the experimental results to validate our thermal model, which can be used to predict device performance under the conditions of outer space. In this limit, thermal fluctuations are halved with reference to a constant-emissivity sample.
Collapse
Affiliation(s)
- Ahmed M Morsy
- Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, 90089, USA.
| | - Michael T Barako
- NG Next Northrop Grumman Corporation, 1 Space Park Drive, Redondo Beach, CA, 90278, USA
| | - Vladan Jankovic
- NG Next Northrop Grumman Corporation, 1 Space Park Drive, Redondo Beach, CA, 90278, USA
| | | | - Mark W Knight
- NG Next Northrop Grumman Corporation, 1 Space Park Drive, Redondo Beach, CA, 90278, USA
| | - Georgia T Papadakis
- NG Next Northrop Grumman Corporation, 1 Space Park Drive, Redondo Beach, CA, 90278, USA.,Department of Electrical Engineering, Ginzton Laboratory, Stanford University, Stanford, CA, 94305, USA
| | - Luke A Sweatlock
- NG Next Northrop Grumman Corporation, 1 Space Park Drive, Redondo Beach, CA, 90278, USA
| | - Philip W C Hon
- NG Next Northrop Grumman Corporation, 1 Space Park Drive, Redondo Beach, CA, 90278, USA
| | - Michelle L Povinelli
- Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, 90089, USA
| |
Collapse
|
7
|
Sherrott MC, Hon PWC, Fountaine KT, Garcia JC, Ponti SM, Brar VW, Sweatlock LA, Atwater HA. Experimental Demonstration of >230° Phase Modulation in Gate-Tunable Graphene-Gold Reconfigurable Mid-Infrared Metasurfaces. Nano Lett 2017; 17:3027-3034. [PMID: 28445068 DOI: 10.1021/acs.nanolett.7b00359] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Metasurfaces offer significant potential to control far-field light propagation through the engineering of the amplitude, polarization, and phase at an interface. We report here the phase modulation of an electronically reconfigurable metasurface and demonstrate its utility for mid-infrared beam steering. Using a gate-tunable graphene-gold resonator geometry, we demonstrate highly tunable reflected phase at multiple wavelengths and show up to 237° phase modulation range at an operating wavelength of 8.50 μm. We observe a smooth monotonic modulation of phase with applied voltage from 0° to 206° at a wavelength of 8.70 μm. Based on these experimental data, we demonstrate with antenna array calculations an average beam steering efficiency of 23% for reflected light for angles up to 30° for this range of phases, confirming the suitability of this geometry for reconfigurable mid-infrared beam steering devices. By incorporating all nonidealities of the device into the antenna array calculations including absorption losses which could be mitigated, 1% absolute efficiency is achievable up to 30°.
Collapse
Affiliation(s)
| | - Philip W C Hon
- Northrop Grumman Corporation, NG Next Nanophotonics & Plasmonics Laboratory, Redondo Beach, California 90278, United States
| | - Katherine T Fountaine
- Northrop Grumman Corporation, NG Next Nanophotonics & Plasmonics Laboratory, Redondo Beach, California 90278, United States
| | - Juan C Garcia
- Northrop Grumman Corporation, NG Next Nanophotonics & Plasmonics Laboratory, Redondo Beach, California 90278, United States
| | - Samuel M Ponti
- Northrop Grumman Corporation, NG Next Nanophotonics & Plasmonics Laboratory, Redondo Beach, California 90278, United States
| | - Victor W Brar
- Department of Physics, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Luke A Sweatlock
- Northrop Grumman Corporation, NG Next Nanophotonics & Plasmonics Laboratory, Redondo Beach, California 90278, United States
| | | |
Collapse
|