Date: Apr 13, 2020 Author: Luke James Source: All About Circuits (
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A research team from the University of Utah in Salt Lake City in partnership with Oblate Optics, Inc. have developed an ultra-thin lens that could be used in the next generation of cameras and imaging equipment.
Using this lens, which is around one-thousandth of an inch thick, the researchers have built a camera that does not require focusing. This offers several benefits over traditional cameras, such as those found in electronics from smartphones to LiDAR systems, which use multiple lenses to build high-quality, focused images.
The researchers published their findings in The Optical Society’s journal for high impact research, Optica, and claim that the lens is able to maintain focus for objects that are around 6 meters apart from each other.
This is said to be achieved through a nanostructure that is patterned on a flat surface to achieve important optical properties to control how light travels. In contrast, a regular lens will use bulky plastic or glass to achieve this.
Eliminating the Need for Focusing
Conventional cameras, regardless of whether they are used in smartphones or high-level industrial equipment, require focusing to ensure that the details of the objects it captures are sharp. If there are several objects at different distances from the camera in the frame, each object must be focused separately.
The lens, which is 1/1000th of an inch thick, is said to eliminate the need for this, allegedly enabling any camera to keep every object in a frame simultaneously in focus.
In the team’s research paper, Rajesh Menon, the team’s leader, says: “Conventional cameras also use multiple lenses to keep different colours of light in focus simultaneously. Since our design is very general, we can also use it to create a single flat lens that focuses all colours of light, drastically simplifying cameras even further.”
A flat lens developed by University of Utah researchers.
The flat lens developed by the University of Utah researchers. Image credited to Dan Hixson/University of Utah College of Engineering
Improving Lens Design
The researchers say that this development came when they realized that there were other ways to direct light besides using conventional lenses to turn parallel light waves into spherical ones which converge into a focal spot. They realized that waves of other shapes could produce a similar effect, thus increasing the number of potential lens designs.
"In stark contrast to what is taught in optics textbooks, our research has shown that there is more than one way that light transmission is affected by an ideal lens,” added Menon.
Applications in Imaging Systems
The lens has many potential applications outside of use in photography and consumer products such as smartphones, say the research team. One application where it could prove to be highly useful is in LiDAR systems for self-driving cars and other autonomous vehicles and systems.
Although LiDAR systems primarily operate with the use of lasers, cameras are used for the identification of things like traffic cones, traffic lights, debris on the road, animals, and more. By eliminating focusing, the lens could mean autonomous vehicles are safer because LiDAR systems will start out with sharper starting images, hastening identification and decision making.
Furthermore, because the design approach that the research team uses can be expanded to create optical components with varying properties—for example, lower cost, higher bandwidth, and easier manufacturability—the cameras used in imaging systems like LiDAR could become even more functional and specialized by reducing factors like weight, complexity, and cost.