What They Say
A group of researchers at the University of Ottowa have developed the concept of a ‘spaceplate’ that can be used to replace the space between lenses in optical systems. The concept was published in Nature Communications and described at Optics.org and exploits the idea of exploiting the angle of a light ray rather than the position.
“To light, a spaceplate looks like more space than it occupies. In a way, the spaceplate is a counterpart to the lens, doing things the lens can’t do to shrink down entire imaging systems”.
The technology was developed as part of work on metasurfaces and metalenses, but is compatible with broadband light in the visible spectrum.
The team is developing the next generation of this technology with the aim of increasing the compression factor and improving the overall performance. Dr. Jeff Lundeen, Canada Research Chair in Quantum Photonics, said,
“We already have some designs to increase the compression factor from 5 to over 100 times, and to increase the total transmission. To continue doing this, we need to come up with a completely new design paradigm.”
Dr. Orad Reshef said,
“It’s surprising that optical elements like lenses have been around for a millennium and their design rules have been well understood for over 400 years, and yet we’re still discovering such fundamental new optical elements for imaging.”
What We Think
This is a really fascinating concept and the attraction for
The article highlights advantages in cameras and smartphones as well as medical applications, but doesn’t mention projection systems. I can’t see from what I read why the concept could not be used in that kind of lens system to reduce the space used. (BR)
Operating principle of a spaceplate. a, A spaceplate can compress a propagation length of deff into a thickness d. For example, a beam incident on the spaceplateat angle ? will emerge at that same angle and be transversely translated by length w (resulting in a lateral beam shift ?x), just as it would for deff of free space. b, Adding a spaceplate to an imaging system such as a standard camera (top) will shorten the camera (center). An ultrathin monolithic imaging system can be formed by integrating a metalens and a spaceplate directly on a sensor (bottom). Credit: Orad Reshef and Jeff Lundeen u Ottawa / Nature Communications.
