For hundreds of years, telescopes have trusted curved glass lenses to bend gentle and convey the cosmos into center of attention. Whilst efficient, those conventional lenses include a significant downside—the extra robust they’re, the bulkier and heavier they grow to be. This limitation has lengthy been a problem for space-based telescopes and satellites, the place weight and dimension are important elements.
Now, a workforce of engineers from the College of Utah has advanced a progressive flat telescope lens that captures shade appropriately whilst detecting faint starlight from far away gadgets. This light-weight, compact optical leap forward may just become area exploration, making long term telescopes thinner, sharper, and extra environment friendly.
Their find out about, printed in Carried out Physics Letters, showcases how this ultra-thin lens can center of attention gentle simply as successfully as conventional curved optics—with out the distortions or shade inaccuracies that experience plagued earlier flat lens designs.
The Downside with Conventional Telescope Lenses
Lenses paintings through bending gentle to amplify far away gadgets. The more potent the magnification, the extra the lens will have to curve to center of attention gentle correctly. Whilst this isn’t a subject matter for small cameras or yard telescopes, astronomical lenses will have to be huge to assemble sufficient gentle from far flung galaxies and exoplanets.
This is the reason observatories and area telescopes like Hubble and James Webb depend on massive, curved mirrors as a substitute of conventional lenses. Mirrors are lighter and can also be thinner than identical lenses, making them preferrred for deep-space imaging. Alternatively, flat lenses have lengthy been a dream for optical engineers—providing a possible choice that mixes the ability of conventional optics with a considerably lowered weight and dimension.
Till now, current flat lenses have struggled with shade distortion. One sort, the Fresnel zone plate (FZP), makes use of concentric ridges to center of attention gentle however fails to supply true colours, because it bends other wavelengths at reasonably other angles, resulting in chromatic aberrations.
That’s the place this new College of Utah design adjustments the sport.
A Modern Flat Lens That Preserves Colour Accuracy
The leap forward comes from a brand new form of multi-level diffractive flat lens, advanced through Professor Rajesh Menon and his workforce on the College of Utah’s Laboratory for Optical Nanotechnologies.
“Our computational tactics urged lets design multi-level diffractive flat lenses with massive apertures that might center of attention gentle around the visual spectrum, and now we have the sources within the Utah Nanofab to in truth cause them to,” stated Menon.
Not like earlier flat lenses, which fight with shade accuracy, the Utah workforce designed microscopically small concentric rings at the lens floor. Those indentations are engineered to center of attention all wavelengths of sunshine on the identical time, making sure a pointy, full-color symbol moderately than one distorted through chromatic aberrations.
“Simulating the efficiency of those lenses over an overly massive bandwidth, from visual to near-infrared, concerned fixing complicated computational issues of very massive datasets,” defined researcher Apratim Majumder, the find out about’s lead writer.
Through moderately controlling the scale and spacing of those microscopic indentations, the workforce was once ready to create a 100 mm-diameter flat lens with an f/2 aperture, able to focusing gentle with an accuracy that competitors typical curved optics.
The concentric rings of microscopic indentations at the researchers’ flat lens are optimized to deliver all wavelengths of sunshine into center of attention on the identical time. Credit score: Menon Lab, College of Utah
Trying out the Flat Lens: Surprising Photographs of the Solar and Moon
To reveal the ability in their flat lens, the researchers examined it on astrophotography goals, taking pictures photographs of the Solar and Moon. The effects confirmed sharp, color-accurate photographs, proving that their lens can be a viable choice to standard telescope optics.
This a hit demonstration is a significant step towards light-weight, full-color imaging techniques for area telescopes, satellites, and airborne observatories.
“Our demonstration is a stepping stone towards growing very massive aperture light-weight flat lenses with the potential of taking pictures full-color photographs to be used in air-and-space-based telescopes,” Majumder stated.
