Lenses must curve, which means designers must add a bit of extra thickness to a smartphone's camera housing to accommodate them. But what if you could simply omit the lenses entirely?
That's what engineers at Caltech are proposing. Their camera design uses sensors and software to mimic how the lense of a digital camera captures light.
"We've created a single thin layer of integrated silicon photonics that emulates the lens and sensor of a digital camera, reducing the thickness and cost of digital cameras," electrical engineering professor Ali Hajimiri told Caltech's newsroom.
The design is a miniature version of a phased array, which is also used in radars and wireless antennas. Instead of capturing a radio signal, through, Caltech's array is made up of several light sensors that activate at slightly different times, which not only allows the camera to focus, but also capture fish-eye and telephoto images. Coupled with algorithms that can precisely control each sensor's timing, the array could result in phones that are not only thinner, but also more versatile at taking photos.
"With our new system, you can selectively look in a desired direction and at a very small part of the picture in front of you at any given time, by controlling the timing with femto-second—quadrillionth of a second—precision," Hahimiri said.
Thinness isn't everything, though: customers of high-end smartphones also expect their cameras to take flawless photos, and companies like Google and Apple encourage those high expectations by touting their cameras' quality. It's unclear if replacing a lense with software would improve quality as much as it saves space, and sample images taken with Caltech's design weren't immediately available.
If their design doesn't catch on in smartphones, the Caltech engineers are also optimistic that astronomers could use it to create powerful but ultra-thin space telescopes.