Getting rid of the lenses …

The Optical Phase Array (OPA) chip can get away of the need for a lenses to focus an image. Credit: Caltech

The usual advice given to new photographers is: “invest your money in good lenses, rather than on the camera, lenses make the difference in photo quality”.
Well, given the innovation created at Caltech that advice might lo longer apply (in the next decade).

A team of researchers have created a chip, OPA – Optical Phase Array, that can make do without lenses managing to focus on a “plane” to capture an image using a completely different process. Rather than requiring all rays bouncing out from a plane at a given distance from the sensor by bending them using lenses (this is what happens when you “focus” on an object, you change the optical architecture of the lenses to have all rays originating from a specific plane to hit the photosensor) the researchers have created a chip whose pixels can capture light rays at slightly different time. The key word is “slightly”: they can delay the capturing by a quadrillionth of a second, that is the time it takes a light beam to cover 0.3µm, it takes light 100 quadrillionth of a second to cover the thickness of the thinnest hair (to give an idea of the number 1 quadrillion is thought to be the number of ants living on the planet).

The feat is achieved by looking at the phase of light beams (by the way this is what Michelson and Morley did in their famous 1887 experiment chasing for the ether, when an extremely precise measurement of light beams speed was required) and using it to process the data.

The chip they created prove the concept, however it won’t make any photographer interested since it has a resolution of 64 pixels, 250,000 times lower than the one we are used today.
So for the time being we better keep our lenses but by the end of the next decade after the mirrorless cameras of this decade we might consider lensless cameras.

About Roberto Saracco

Roberto Saracco fell in love with technology and its implications long time ago. His background is in math and computer science. Until April 2017 he led the EIT Digital Italian Node and then was head of the Industrial Doctoral School of EIT Digital up to September 2018. Previously, up to December 2011 he was the Director of the Telecom Italia Future Centre in Venice, looking at the interplay of technology evolution, economics and society. At the turn of the century he led a World Bank-Infodev project to stimulate entrepreneurship in Latin America. He is a senior member of IEEE where he leads the New Initiative Committee and co-chairs the Digital Reality Initiative. He is a member of the IEEE in 2050 Ad Hoc Committee. He teaches a Master course on Technology Forecasting and Market impact at the University of Trento. He has published over 100 papers in journals and magazines and 14 books.