In the past decade researchers have made steady progress developing technologies that produce varying levels of cloaking. While these efforts have been groundbreaking and successful they’ve relied on exotic materials that are expensive to produce. As cloaking tech continued toward ever increasing complexity, however, researchers at the University of Rochester created a simple, easy to build cloaking device.
Constructed from a series of four lenses, the Rochester cloak is made possible through the precise positioning of each optical component. When coupled in a specific series, two f1 and two f2 lenses can be aligned to make an object passing through their view disappear. What’s astounding about the Rochester design is not just its simplicity, but also its ability to obscure objects regardless of a user’s viewing angle. In previous cloaking technologies exacting viewing angle were required to achieve the desired effect, rendering them a bit useless – that is not the case with this new optical design. In addition to its wide field of view the Rochester cloak has the ability to scale up as the diameter of its lenses increase.
While the Rochester cloak is, without question, a major leap forward in cloaking tech it’s far from perfect. “This cloak bends light and sends it through the center of the device, so the on-axis region cannot be blocked or cloaked,” said Choi. What Choi means is that in his team’s initial iteration of their design a doughnut shaped field was rendered invisible, while a small central section escaped the cloak’s cover. However, with a bit of tweaking and a slightly more complicated design that artifact has been removed.
Though cloaking of the Rochester variety might seem to have few practical applications, the Rochester team was quick to point out that their discovery could make a major difference in everyday life. Armed with cloaking spectacles surgeons could see through their hands to better observe what they’re working on. Furthermore, semi drivers could employ the same tools to eliminate blind spots, making highways much safer for everyone.
1. Purchase 2 sets of 2 lenses with different focal lengths f1 and f2 (4 lenses total, 2 with f1 focal length, and 2 with f2 focal length)
2. Separate the first 2 lenses by the sum of their focal lengths (So f1 lens is the first lens, f2 is the 2nd lens, and they are separated by t1= f1+ f2)
3. Do the same in Step 2 for the other two lenses
4. Separate the two sets by t2=2 f2 (f1+ f2) / (f1— f2) apart, so that the two f2 lenses are t2 apart
Image Courtesy of University of Rochester