Engineers have developed a way to create a paper-thin camera with no lens or mechanical components.
Over the years, cameras have gotten a lot thinner and ‘smarter’, with cameras that can send alerts when it is time to order more food and use ultraviolet light to monitor skin damage. However, no matter how thin or how sophisticated, traditional cameras require a curve in order to function – the curve bends the path of incoming light and focuses it onto film or (in the case of a digital camera) an image sensor. As a result, traditional cameras can never be truly flat. Now, engineers at CalTech have developed an ultra-thin camera that can create images without a lens or any mechanical parts. They have replaced the mechanically-controlled lens with a wafer-thin optical phased array, which has a large array of light receivers, allowing the camera to selectively look in different directions and focus on different things.
Phased arrays are collections of individual transmitters, which send out the a signal as waves. These waves amplify the signal in one direction while cancelling it out elsewhere, allowing the creation of a tightly focused beam to be electronically controlled. Reza Fatemi, lead author of the paper explains, “What the camera does is similar to looking through a thin straw and scanning it across the field of view. We can form an image at an incredibly fast speed by manipulating the light instead of moving a mechanical object.”
The team developing the camera is led by Ali Hajimiri, Bren Professor of Electrical Engineering and Medical Engineering in the Division of Engineering and Applied Science at Caltech. Hajimiri’s team has already unveiled a one-dimensional version of the camera that acts like a lensless barcode reader with no mechanical moving part. Now the team are building a low resolution, two-dimensional version as proof of concept. Next, they will develop a scaled up version with higher resolution and sensitivity. The team anticipate that the applications for a camera without any mechanical movement or lenses could one day include imagers that could look like wallpaper or wearable fabric. What other uses can you think of for a camera as thin as a piece of paper?