Engineers have created a completely flat lens with a 180-degree viewing angle
The fisheye lens has a wide range of applications due to the fact that it allows you to capture a lot of information in the frame. However, this type of lens is extremely bulky and expensive to manufacture. Engineers at the Massachusetts Institute of Technology have reported achieving exactly the same effect using a flat metal lens.
Fisheye is a type of ultra-wide-angle lens. They are made of multiple pieces of curved glass that scatter incident light to create wide, distorted images. Due to the specifics of production, they are bulky and often expensive. The flat lens developed by American researchers allows for clear panoramic images with a 180-degree viewing angle.
The new lens consists of a single millimeter-thick flat piece of glass covered on one side with tiny structures that scatter incident light to produce panoramic images, just like conventional curved multi-element lenses do. Now the new lens only works with the infrared part of the spectrum, but engineers say that it can be modified to capture images in the spectrum visible to the human eye. To do this, you will have to make the optical elements smaller, also replacing the material itself.
"This design comes as somewhat of a surprise, because some have thought it would be impossible to make a metalens with an ultra-wide-field view. The fact that this can actually realize fisheye images is completely outside expectation," says Juejun Hu, associate professor in MIT’s Department of Materials Science and Engineering.
The development may well find applications in smartphones, laptops, action cameras, and other portable devices where it is difficult to install traditional fisheye lenses.