Flat lenses promise to slash weight of orbiting optics

Diffraction harmonic lens weighs only 5 grams and replaces a complex and massive system of lenses and mirrors similar to the one that is used in telephoto lenses with a focal length of 300 mm and a weight of 500 grams (Samara University)

8 August 2018

Scientists at Samara National Research University in Russia have devised a way to make flat lenses which, combined with digital processing, may give nanosatellites and small drones the imaging power of a 300mm telephoto lens for just 100th of the mass. Writing in the IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, professor Artem Nikonorov and colleagues describe diffraction lenses that they believe can replace conventional lenses made of a dozen or more elements. These 256-layer “ultralight harmonic lenses” weigh as little as 5 grams, he says, but can provide images comparable in quality to those returned from consumer cameras and mobile phones.

And, he says, the flat lenses can be manufactured using techniques similar to those used to make compact discs, for about the same cost.

Digital processing to remove distortions and correct colour – with convolutional neural networks – takes about 1 second. Nikonorov and his team believe their technology may be able to providing 18m resolution images of the Earth’s surface from a nanosatellite, compared to optical systems on the market providing 40m resolution.

The research group hopes further improvements in manufacturing and digital processing will overcome image distortion.

Diffraction lens production process borrows techniques from CD manufacture (Samara University)