《科学美国人》评选出2019年十大新兴技术

最新评论

redplum 2019-11-27 00:01

真牛逼啊

tassy 2019-11-27 01:32

新技术真牛啊

mang2004 2019-11-27 05:28

Engineering : Tiny Lenses Will Enable Design of Miniature Optical Devices ?(L?X&)v  
Thin, flat metalenses could replace bulky glass for manipulating light x)sDf!d4bi  
5xV/&N  
By Alberto Moscatelli DmpJzHj|  
j9fL0$+FI  
As phones, computers and other electronics have grown ever smaller, their optical components have stubbornly refused to shrink. Notably, it is hard to make tiny lenses with traditional glass-cutting and glass-curving techniques, and the elements in a glass lens often need to be stacked to focus light properly. Engineers have recently figured out much of the physics behind much smaller, lighter alternatives known as metalenses. These lenses could allow for greater miniaturization of microscopes and other laboratory tools, as well as of consumer products, such as cameras, virtual-reality headsets and optical sensors for the Internet of Things. And they could enhance the functionality of optical fibers. 6!=9V0G~  
cFNtY~(b  
A metalens consists of a flat surface, thinner than a micron, that is covered with an array of nanoscale objects, such as jutting pillars or drilled holes. As incident light hits these elements, many of its properties change—including its polarization, intensity, phase and direction of propagation. Researchers can precisely position the nanoscale objects to ensure that the light that exits the metalens has selected characteristics. What is more, metalenses are so thin that several can sit atop one another without a significant increase in size. Researchers have demonstrated optical devices such as spectrometers and polarimeters made from stacks of these flat surfaces. /<N
t$n  
?[fl$EG  
In a major breakthrough last year, researchers solved a problem called chromatic aberration. As white light passes through a typical lens, rays of its varied wavelengths get deflected at different angles and thus focus at different distances from the lens; to fix this effect, engineers today need to layer lenses in a finicky alignment. Now a single metalens can focus all the wavelengths of white light onto the same spot. Beyond creating this “achromatic” metalens, scientists have developed metalenses that correct other aberrations, such as coma and astigmatism, which cause image distortions and blurring. T-cVM>u\D  
@3=<wz<  
In addition to reducing size, metalenses should ultimately lower the cost of optical components because the diminutive lenses can be manufactured with the same equipment already used in the semiconductor industry. This feature raises the alluring prospect of fabricating, say, a tiny light sensor's optical and electronic components side by side. }Mlz\'{  
{1&,6kJF&9  
For now, however, expenses are still high because it is difficult to precisely place nanoscale elements on a centimeter-scale chip. Other limitations also need addressing. So far metalenses do not transmit light as efficiently as traditional lenses do—an important capability for such applications as full-color imaging. In addition, they are too small to capture a large quantity of light, which means that, at least for now, they are not suited to snapping high-quality photographs. W p* v Vv  
>t<R6f_Q0  
Nevertheless, in the next few years the tiny lenses will probably make their way into smaller, easier-to-manufacture sensors, diagnostic tools such as endoscopic imaging devices, and optical fibers. Those potential applications are appealing enough to have attracted research support from government agencies and such companies as Samsung and Google. At least one start-up, Metalenz, expects to bring metalenses to market within the next few years. qhGhUyNX  

tomryo 2019-11-27 07:25

《科学美国人》评选出2019年十大新兴技术

从业者007 2019-11-27 07:58

2019年十大新兴技术

daite1978 2019-11-27 08:07

真牛逼啊

songshaoman 2019-11-27 08:12

光看 就觉着牛

stoutman 2019-11-27 08:26

风能、太阳能和其他非水力发电的可再生能源将成为未来两年电力组合中增长最快的部分。但是，这些能源的间歇性意味着电力公司需要一种方法，在没有太阳照耀、风平浪静的时候，将能源储下来。

thorn12345 2019-11-27 08:27

出2019年十大新兴技

谭健 2019-11-27 08:46

真牛逼啊