Smaller, sleeker lenses that don’t degrade image quality? Oh Harvard, what will you come up with next?
When it comes to the lenses of optical devices such as video cameras, DSLRs and binoculars there aren’t too many variations in terms of design. In order to accurately and comfortably capture the entire visible spectrum of light, current optical devices utilize several different lenses of varying thickness and materials stacked atop one another. While this does result in a high resolution, it can also add greatly to the bulk of the device. However thanks to a talented team of researchers at Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) we may be on the verge of a new era in lense technology via new advances that could revolutionize the game. This video below should help shed a little more light (pun very much intended):
Referred to as Metalenses, this 21st century reimagining of the traditional lens bypasses the complicated and often space-consuming process of stacking various lenses atop one another in favor of one a single, flat design. The first of its kind, metalenses are essentially flat surfaces that employ nanostructure technology to focus the entire visible spectrum of light – including white – in the same exact spot and quality of high resolution as conventional lenses.
“Metalenses have advantages over traditional lenses,” stated Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at SEAS as well as the senior author of the research. “Metalenses are thin, easy to fabricate and cost effective. This breakthrough extends those advantages across the whole visible range of light. This is the next big step.”
“One of the biggest challenges in designing an achromatic broadband lens is making sure that the outgoing wavelengths from all the different points of the metalens arrive at the focal point at the same time,” added Wei Ting Chen, postdoctoral fellow at SEAS and paper contributor. “By combining two nanofins into one element, we can tune the speed of light in the nanostructured material, to ensure that all wavelengths in the visible are focused in the same spot, using a single metalens. This dramatically reduces thickness and design complexity compared to composite standard achromatic lenses.”
Confused? So was I. Basically, each wavelength on the visible spectrum moves through various materials at different speeds. If each wavelength arrived independently at various times, it would result in image distortion. It’s for this reason traditional lenses are curved and multilayered as to accommodate the varying speeds of each wavelength. Metalenses utilize a system of paired titanium dioxide nanofins to ensure each light arrives at the same time without the need of layered lenses. The result is a smaller, sleeker, cheaper lens that simultaneously matches the quality of traditional lenses.
So what does this mean for VR & AR? Hopefully smaller, sleeker headsets for one. Much like other cameras and lens-based devices, VR & AR relies heavily on a system of high quality lenses in order to function properly. A smaller pair of lenses could drastically reduce the size and weight of current headset hardware which could in turn increase immersion. After all, the most engaging moments in VR and AR are the ones we forget we’re actually wearing a headset.