Wall change mirror! Chinese Northwestern University Chinese R & D Perspective camera, light wave holographic imaging see through everything

Edit: Little Salted Fish David

[Xinzhiyuan Guide] Researchers from Northwest University invented a new high -resolution see -through camera that can see things that could not be seen before through scattering medium, such as skin, fog, etc. Synthetic Wavelength Holography.

How can I have a pair of “perspective eyes”?

No, researchers at Northwest University invented a camera that can be seen through almost anything, allowing you to change your eyes in seconds!


Based on this, researchers at Northwestern University have invented a new high -resolution camera that can see things that they can’t see before through scattering medium, such as skin, fog, and even human skulls.

This new method called Synthetic Wavelength Holography is to indirectly scatter the coherent light to the hidden objects, and then lightly scatter these objects and spread back to the camera.

At this time, using a algorithm to rebuild the scattered light signal, you can reveal the hidden object.

Due to its high time resolution, this method also has the potential of fast -moving object imaging, such as cars driving at the heart or street angle of the heart or street angle, so it can be used for car early warning navigation systems or non -invasive medical imaging.


The research was published in the “Nature · Communication” magazine on November 17.

Perm the objects behind the obscure or scattering medium. This relatively new research field is called “Non-Line-OF-Sight (NLOS).

Compared with related non -visual imaging technology, Northwestern University methods can quickly capture large -scale full -scale images with Asian millimeter accuracy.


Under this resolution, the calculation camera can be used through the skin, and even the smallest capillaries can be seen.

This method currently has obvious potential in non -invasive medical imaging, automobile early warning navigation system, and industrial testing of closed space, but researchers believe that its potential application value is endless.

“Our technology will usher in a new wave of imaging,” said the first author of the study, Florian Willomitzer of the McCocker Institute of Engineering.

Florian Willomitzer

“Our current sensor prototype uses visible light or infrared light, but the principle is universal and can be extended to other wavelengths. For example, the same method can be applied to radio waves of space exploration or water sound imaging. It’s just touched the surface. “

Florian Willomitzer is a research assistant professor of electrical and computer engineering at the School of Electrical and Computer Engineering. The co -authors of this article include Oliver COSSAIRT, an associate professor of computer science, electrical and computer engineering, and former doctoral student Fengqiang Li.

Oliver cossairt

Fengqiang li

Intercept scattered light

Seeing a corner and imagining an organ in the human body seemed to be very different, but Florian Willomitzer said that they were actually closely related. Both involve scattering media. Among them, when the object is scattered in the object, the direct image of the object is invisible.

“If you tried to cover the flashlight with your hands, then you have experienced this phenomenon,” Florian Willomitzer said.


“You see a highlight on the other side of your hand. In theory, your bones should have a shadow to reveal the structure of the bone. However, the light passing through the bones scattered in all directions in the tissue, completely blurring the shadow image. “

Therefore, the goal of the researcher is to intercept the scattered light to rebuild the inherent information of its dissemination time, thereby revealing the hidden objects, but this also brings challenges.

“There is nothing faster than the speed of light, so if you want to measure the time of light high accuracy, then you need a very fast detector.” Willomitzer said, “And this detector is very expensive.”

Tailor -made light waves


In order to eliminate the demand for fast detectors, Florian Willomitzer and his colleagues merged with light waves from two laser to produce a synthetic light wave. This light wave can be customized specifically for the holographic imaging in different scattered scenarios.

“If you can capture the entire light field of the object in the holographic chart, then you can completely rebuild the three -dimensional shape of the object.” Florian Willomitzer explained. “We perform holographic imaging at the corner or through the scatter. , Use a synthetic wave to replace ordinary light waves. “


The picture above shows the technical architecture of the target imaging of the corner and the scattered medium imaging. Image source: Nature Communications

The current sensor prototype uses visible light or infrared light, but the principle behind is common and can be extended to other wavelengths. The same method can be applied to space exploration, or wireless radio waves with water sound imaging. The results of this research can be used in many fields in the future, and the current research is just the beginning.


In recent years, many studies have been studied based on the principle of non -visual imaging (NLOS) and trying to restore hidden targets. But these methods usually have different degrees of problems. Either the resolution is low, the viewing angle is very small, the time -consuming grating scan, or a large detection area is required to measure the scattered light signal.

Experimental demonstration and resolution assessment of diagonal target imaging and its resolution evaluation

The research of Northwestern University solved these problems. It was the first method to imagine the imaging near the corner through the scattered medium. At the same time, it has the advantages of high space resolution, high time resolution, small exploration area, and large angle viewing field.

In other words, the camera can imagine the tiny characteristics and large hidden objects in the narrow space with high resolution, and the movement target is not a problem.

Turn the wall “into a mirror”

Because light can only be transmitted on the straight path, there must be an opaque barrier (such as walls, shrubs, or cars) to allow new devices to see around the corner.

The light is sent from the sensor unit (which can be installed on the top of the car), reflected from the obstacles, and then illuminated on the corner object. Then, the light reflects the barrier to the detector of the sensor unit.


Continuous wave (CW) adjustable laser can illuminate the scene with two slightly different wavelength λ1 and λ2.

“This is like we can plant a virtual computing camera on every distant surface, looking at the world from a surface perspective,” Florian Willomitzer said.

For those who drive through the mountains or winding through the rural forest, this method can prevent accidents by displaying other cars or deer near the curve.

“This technology turns the wall into a mirror. It has become better because this technology can also work at night and fog,” Florian Willomitzer said.

Imaging result

In this way, high -resolution technology can also replace (or supplement) endoscopes for medical and industrial imaging. The synthetic wavelength holographic surgery can use light to observe many wrinkles in the intestine, rather than a flexible camera that can turn and twist in the narrow space, such as for colonoscopy.

Similarly, synthetic wavelength holographic surgery can be used inside the device when the industrial equipment is running -this is a feat that is currently incapable of endoscope.


“If you have a turbine that runs and wants to check the defects, you usually use endoscopes,” said Florian Willomitzer. “But some defects only appear when the device is running. When the turbine is running, you cannot use the endoscopic to see the turbine from the front. Our sensor can observe the interior of the turbine in the operation to detect the structure of less than 1 mm.”


Although this technology is only a prototype, Florian Willomitzer believes it will eventually be used to help drivers avoid accidents. He said: “There is still a long way to go before we see this imaging device built in a car or approved for medical applications.” Maybe 10 years or even longer, but it will come. “


Reference materials:

https://www.mccormick.northwestern.edu/news/articles/2021/11/new-holographic-camera-sees-with-high-precision/www.nature.com/www.nature.com/www.nature.com S41467-021-26776-W#SEC2

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