Researchers create thinner and lighter optical lens for smartphones
American scientists have developed a new type of lens that is much lighter and thinner than regular lenses for smartphone cameras. This could lead to the development of ‘flat’ smartphones without the camera or camera island sticking out.
According to one of the researchers, conventional smartphone camera lenses are a few millimeters thick, while the newly developed lens has a thickness of a few micrometers, 10μm to be precise. This makes the lens about a thousand times thinner than regular lenses. In addition, the researchers say that the lens is a hundred times as light. According to the researchers, these advantages do not have to be accompanied by disadvantages in terms of performance.
A conventional curved lens captures light from outside, which is refracted multiple times by the different refractive indices of air and glass and thus changes direction. Thus, it eventually falls on the camera sensor, where the light is converted into electricity. The new lens consists of a multitude of microstructures, with each individual structure scattering the light, as it were; refraction causes it to change direction so that it hits the sensor. According to the researchers, these microstructures should be seen as very small pixels of a lens, or scattering elements. They are not lenses in themselves, but all together they form a lens.
The result is a lens that is flat and not curved. A conventional lens consists of curved surfaces and gets thicker with increasing resolution. To do this, the light must be refracted at greater angles, which requires a reduction in the radius of the curvature. That makes the lens thicker and heavier. This would no longer be necessary due to the application of the microstructures.
The researchers argue that the lens they have developed could lead to smartphone cameras that do not protrude. In addition, the thinner lens is suitable for infrared recordings, in which the temperature is mapped via thermography. This makes it possible to search for heat sources. For example, the scientists say their lens could be used to create lighter military drones that can stay airborne for longer, performing night missions or searching for wildfires and victims of natural disasters. In addition, their development is potentially good news for soldiers, who could use much lighter night vision goggles.
In principle, the new lens could be produced more cheaply, as the design allows them to be made from plastic instead of glass. The research team says it has developed a fabrication process with a new type of polymer, where algorithms can calculate the geometry of the microstructures.
The scientists have published about the lens in the journal Proceedings of the National Academy of Sciences, under the title Broadband lightweight flat lenses for long-wave infrared imaging. The research was funded by the National Science Foundation and the US Office of Naval Research.