The new lens without lens sees in 3D using the old pine hole technology

A system without objective produces half-infrared infrared images, even in low light and long distances, creating new opportunities for improved night vision, industrial inspections and environmental surveillance.

Based on the secular principle of imaging with stenopated, researchers have developed a high performance infrared median imaging system that works without lenses. This new camera is capable of producing exceptionally clear images on a wide range of distances and under low light conditions, which makes it suitable for environments where conventional cameras often fight.

“Many useful signals are in the infrared environment, such as heat and molecular digital fingerprints, but the cameras working at these wavelengths are often noisy, expensive or require cooling,” said the head of the Heping Zeng Zeng Research Team of the East China University. “In addition, traditional lens -based configurations have a limited depth and need a careful design to minimize optical distortions. We have developed an approach without high and without objective that offers a much greater vision and field of vision than other systems. ”

In an article published in the journal OPTICALThe team describes how they use light to create a small “optical access hole” inside a non -linear crystal. This crystal also converts the infrared image into a visible image. With this technique, they produced light-infrared infrared images with a depth of field greater than 35 cm and a field of vision exceeding 6 cm. The same configuration also allowed them to capture 3D images.

“This approach can improve night safety, industrial quality control and environmental surveillance,” said Kun Huang, member of the East China University research team. “And because it uses the simpler optics and standard silicon sensors, it could possibly make the infrared imaging systems more affordable, portable and energy efficient.[{” attribute=”” tabindex=”0″ role=”link”>terahertz wavelengths, where lenses are hard to make or perform poorly.”

Pinhole imaging reimagined

Pinhole imaging is one of the earliest known methods for creating images, first described by the Chinese philosopher Mozi in the 4th century BC. In a traditional pinhole camera, light enters through a tiny opening in a sealed box and projects an inverted image of the outside scene onto the inner surface opposite the hole. Unlike systems that rely on lenses, pinhole imaging does not suffer from distortion, offers unlimited depth of field, and functions across a broad spectrum of wavelengths.

To adapt these benefits for modern infrared imaging, the research team used a powerful laser to generate an “optical hole,” or artificial aperture, within a nonlinear crystal. Thanks to the crystal’s unique optical properties, the infrared image is converted into visible light, enabling it to be captured by a conventional silicon camera.

https://www.youtube.com/watch?v=HuzModatoye
The video shows the median infrared imagery system capturing clear images of a resolution test target because it is moved to 9 cm, demonstrating the large capacity of the field of the lens without lens. Credit: Kun Huang, normal university of eastern China

According to the researchers, a crystal specially designed with a structure at gas period – accessible to the acceptance of light from many different angles – was crucial to create a large field of vision. In addition, the cross -conversion detection method naturally reduces noise, allowing the system to operate effectively even in very low light conditions.

“Imaging without non -linear holes without lens is a practical way to make medium infrared imaging without distortion, at great depth and in great view, with high sensitivity,” said Huang. “Ultra-colorful synchronized laser pulses also provide an integrated ultraifast time holder that can be used for a sensitive imaging of flight time, even with very few photons.”

After understanding that an optical pine hole radius of approximately 0.20 mm produced net and well -defined details, the researchers used this opening size for target image of 11 cm, 15 cm and 19 cm. They obtained net imaging at the medium infrared wavelength of 3.07 μm, over all distances, confirming a large depth range. They were also able to keep the pictures clear for objects placed up to 35 cm, demonstrating a great depth of field.

3D imagery without lentils

Investigators then used their configuration for two types of 3D imaging. For the imaging of 3D flight time, they imagined a mate ceramic rabbit using synchronized ultra-rapid impulses as optical door and were able to reconstruct the 3D shape with axial precision at the micron level. Even when the input has been reduced to around 1.5 photons per impulse – simulating very low light conditions – the method has further produced 3D images after a scatter based on the correlation.

They also carried out depth imaging with two snapshot by taking two photos of a “ECNU” target stacked at slightly different object distances and using those to calculate the sizes and true depths. With this method, they were able to measure the depth of objects on a beach of about 6 centimeters, without using complex pulsed synchronization techniques.

Researchers note that the average infrared non -linear hole imaging system is always proof of concept that requires a relatively complex and bulky laser configuration. However, as new non -linear materials and integrated lighting sources are developed, technology should become much more compact and easier to deploy.

They are now working to make the system faster, more sensitive and adaptable to different imaging scenarios. Their plans include an increase in conversion efficiency, the addition of dynamic control to reshape the optical sloo hole for different scenes and prolong the operation of the camera through a wider medium infrared beach.

Refraced: “Noonarflem II, Yanan, the fen, Heep and Jianan Fang lining, OPTICAL.
Two: 10.1364 / Optics. 566042

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