Traditional cameras—even those on the thinnest of cell phones—cannot be truly flat due to their optics: lenses that require a certain shape and size in order to function. At Caltech, engineers have developed a new camera design that replaces the lenses with an ultra-thin optical phased array (OPA). The OPA does computationally what lenses do using large pieces of glass: it manipulates incoming light to capture an image.
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"The applications are endless," says graduate student Behrooz Abiri (MS '12), coauthor of the OSA paper. "Even in today's smartphones, the camera is the component that limits how thin your phone can get. Once scaled up, this technology can make lenses and thick cameras obsolete. It may even have implications for astronomy by enabling ultra-light, ultra-thin enormous flat telescopes on the ground or in space." 
"The ability to control all the optical properties of a camera electronically using a paper-thin layer of low-cost silicon photonics without any mechanical movement, lenses, or mirrors, opens a new world of imagers that could look like wallpaper, blinds, or even wearable fabric," says Hajimiri. Next, the team will work on scaling up the camera by designing chips that enable much larger receivers with higher resolution and sensitivity. 
 
https://www.caltech.edu/news/ultra-thin-camera-creates-images-without-lenses-78731