Synthetic Wavelength Holography

Synthetic Wavelength Holography

Imaging through scattering media or around corners at high resolution

Synthetic Wavelength Holography introduces a novel solution to image hidden objects through scatterers or non-line-of-sight geometries at the physical space bandwidth limit. Current state-of-the-art approaches are either technically limited by the low spatial and temporal resolution of time-of-flight detectors, or by a very narrow viewing angle in which the hidden object can be reconstructed. In our approach, we utilize frequency heterodyning to beat together light at two closely spaced optical frequencies to produce a low frequency ‘synthetic wave’ (beat wave), largely immune to the unknown scattering processes between hidden object and detector. By applying the latest full-field lock-in detector technology, we are able to capture a ‘synthetic hologram’ of the hidden object within milliseconds. Since the ‘synthetic wavelength’ is freely tunable, the captured hologram provides a window to fully reconstruct the three-dimensional light field of the hidden scene at at high space-bandwidth.

The general concept of ‘synthetic waves’ has potential applications at many different scales and wavebands, including radar, ultrasound, or X-ray. In the optical waveband the ability to look around corners or through scattering media has many potential applications in medicine, naval sciences, earth, and planetary sciences as well as automotive sensing and material sciences. Looking deeper through tissue, novel endoscopic imaging methods, or imaging through dense fog or atmospheric turbulences are just a few potential applications.

Jump to: [Publications], [News and Press], [Related Talk Recordings]

Related Talk Recordings

F. Willomitzer
Synthetic Wavelength Holography – Imaging around Corners and through Scattering Media at the Physical Space-Bandwidth Limit
Physics Colloquium Talk Series, University Erlangen-Nuremberg, Germany, 2021
[Full Video]
F. Willomitzer
Fundamental Limits in Computational 3D Imaging – From Novel 3D Cameras to Looking around Corners
Beyond the Patterns Talk Series, University Erlangen-Nuremberg, Germany, 2021
[Full Video] , [Jump to Project (23:42)]


Fast Non-Line-of-Sight Imaging with High-Resolution and Wide Field of View using Synthetic Wavelength Holography
F. Willomitzer, P. Rangarajan, F. Li, M. Balaji, M. Christensen, O. Cossairt.
Nature Communications 12, 6647 (2021)

Synthetic Wavelength Holography: An Extension of Gabor’s Holographic Principle to Imaging with Scattered Wavefronts
F. Willomitzer, P. Rangarajan, F. Li, M. Balaji, M. Christensen, O. Cossairt.
arXiv Preprint

Spatially resolved Indirect Imaging of objects beyond the line of sight
P. Rangarajan, F. Willomitzer, O. Cossairt, MP. Christensen
Proc. SPIE 11135, Unconventional and Indirect Imaging, Image Reconstruction, and Wavefront Sensing 2019

Non-Line-of-Sight Imaging with Superheterodyne Remote Digital Holography
F. Willomitzer, F. Li, M.M. Balaji, P. Rangarajan, O. Cossairt
OSA Computational Optical Sensing and Imaging, CM2A. 2

Non-Line-of-Sight Imaging using Superheterodyne Interferometry
F. Willomitzer, F. Li, M.M. Balaji, P. Rangarajan, O. Cossairt.
OSA Computational Optical Sensing and Imaging, CM2E. 1

Synthetic Wavelength Holography in the News

Official Northwestern research news release:
“New holographic camera sees the unseen with high precision” (Northwestern Now Research News, Nov. 17, 2021)
For Journalists: News release for media contacts and assets.

Research news featured on Northwestern websites:
[Northwestern McCormick School of Engineering (retrieved Nov. 18, 2021)]
[Northwestern Electrical and Computer Engineering (retrieved Nov. 18, 2021)]
[Northwestern Computer Science (retrieved Nov. 18, 2021)]

Research news featured on external websites (selection):

Newsweek: “This Holographic Camera Can See Around Corners, Under Human Skin” (Nov. 19, 2021) “Northwestern University camera sees around corners” (Nov. 18, 2021) “New holographic camera sees the unseen with high precision” (Nov. 17, 2021)

Daily Mail: “Powerful holographic camera is developed that can see through …” (Nov. 19, 2021)

AI in Healthcare: “Novel camera images objects around corners, behind barriers” (Nov. 19, 2021)

Science X: “Best of Last Week – Camera sees around corners, ….” (Nov. 22, 2021)

New Atlas: “Holographic camera reconstructs objects around corners in milliseconds” (Nov. 17, 2021)

IFL Science: “New Holographic Camera Can See Around Corners – Or Inside Your Skull” (Nov. 19, 2021)

Mashable: “Researchers Develop Camera That Can See Through Skin And Around Corners” (Nov. 18, 2021)

Universal-Sci: “Scientists developed a remarkable camera that can see around corners” (Nov. 17, 2021)

ZME Science: “Holographic camera can see around corners or even through the skin” (Nov. 18, 2021)

Pressetext (German): “Neuartige Kamera zeigt versteckte Objekte” (Nov. 18, 2021)

VIDEO: Yahoo News (German): “Neue Technologie: Holografische Kamera kann um Ecken sehen” (Nov. 18, 2021)

FutureZone (German): “Neue holografische Kamera macht das Unsichtbare sichtbar” (Nov. 17, 2021)

Germanic (German): “Neue holografische Kamera sieht das Unsichtbare mit hoher Präzision” (Nov. 17, 2021)

RT News (Spanish): “Inventan una cámara holográfica que permite ver dentro del cuerpo y detrás de las esquinas con alta precisión ” (Nov. 19, 2021)

EuropaPress (Spanish): “Nueva cámara holográfica ve lo invisible con alta precisión” (Nov. 17, 2021)

Trust My Science (French): “Une caméra qui permet de voir à travers les objets” (Nov. 17, 2021)

Engineers Online (Dutch): “Nieuwe holografische camera kijkt om hoekjes en ziet het ongeziene met grote precisie” (Nov. 23, 2021)

More research news featured on other external websites:
[ScienceDaily] | [SciTechDaily] | [SpaceLiveNews] | [Unite AI] | [AZO Optics] | [VIDEO: MSN News (German)] | [VIDEO: (German)] | [Newsfounded] | [Nerdswire] | [Florida News Times] | [PetaPixel] | [Brinkwire] | [Remonews] | [Futurism] | [InterestingEngineering] | [TodayIn24] | [Engineering and Technology] | [XNewsNet] | [NewsBeezer] | [CVBJ] | [The Washington Newsday] | [CaliforniaNewsTimes] | [ScienceTimes] | [Techeblog] | [NachWelt (German)] | [WoonderfulEngineering] | [6parkNews] | [ScienceNet (Chinese)] | [Newscon] | [iTechpost] | [WorldIndustrialReporter] | [California18] | [Jioforme] | [Techgamingreport] | [Newsbrig] | [Algulf] | [Funtitech] | [Leakherald] | [Shouzy] | [NewsInseconds] | [MessageToEagle] | [XNewsNet] | [MarketResearchTelecast] | [ScienceSprings] | [MORE…]

Florian Willomitzer
Research Assistant Professor