Ah ha!
Posted on 06/05/2016 9:26:49 AM PDT by Utilizer
A flat lens made of paint whitener on a sliver of glass could revolutionise optics, according to its US inventors.
Just 2mm across and finer than a human hair, the tiny device can magnify nanoscale objects and gives a sharper focus than top-end microscope lenses.
It is the latest example of the power of metamaterials, whose novel properties emerge from their structure.
Shapes on the surface of this lens are smaller than the wavelength of light involved: a thousandth of a millimetre.
"In my opinion, this technology will be game-changing," said Federico Capasso of Harvard University, the senior author of a report on the new lens which appears in the journal Science.
The lens is quite unlike the curved disks of glass familiar from cameras and binoculars. Instead, it is made of a thin layer of transparent quartz coated in millions of tiny pillars, each just tens of nanometres across and hundreds high.
(Excerpt) Read more at bbc.com ...
2mm is the size of the entire lens comprised of jillions of the tiny pillars of titanium dioxide.
There is no way we are NOT in a trade situation with extraterrestrials, who are giving us technology.
My butcher grampa had an incident, not quite as serious. He backed into the meat grinder. Got a little behind in his work.
----Discontinuous redirection
In 2011, however, Federico Capasso and colleagues at Harvard University showed that, if the phase of light waves could be changed discontinuously, the light could be redirected as desired using a flat surface. In their original work, this was achieved using resonant metallic antennas that interfered directly with the electric field of the light. But the antennae were difficult to manufacture and highly inefficient.
Researchers have since shown that phase discontinuities can also be imprinted by using tiny subwavelength elements made of silicon. These imprint a shift in the so-called Pancharatname–Berry phase of the light waves, by imparting a spatially dependent polarization shift as they pass through the elements. These elements are simpler to manufacture and focus transmitted visible light more efficiently, but they still absorb or reflect too much light to make a viable commercial lens.
Capasso's team has now developed a new technique to fabricate these tiny "nanofins", using electron beam lithography to pattern a resist before depositing a very thin layer of titanium oxide – which transmits visible wavelengths much better than silicon – onto the resist to produce the metasurface. The researchers used their technique to fabricate titanium-oxide metalenses designed to focus light at different visible wavelengths. Titanium nanofins
The focusing efficiencies of the lenses were unprecedented for visible-light metalenses: the lens designed for 405 nm (violet) light brought 86% of the incident light to a focus. The lenses also had much higher numerical apertures than previous metalenses, allowing them to focus light from a wider angle to a single spot. This in turn produced focal spots smaller than the light's wavelength, and smaller than those achievable with a state-of-the-art commercial objective containing multiple refractive lenses. ----
The "bad kid" in my grade school had a monster lens. One day in class I smelled something and then yelled in pain. Went right through my shirt, which was a cotton Oxford uniform shirt.
Does this mean my coke-bottle eyeglasses may become obsolete?
a search will show a lot of links: eyeglasses progressive lenses
I hate when that happens.
“There is no way we are NOT in a trade situation with extraterrestrials, who are giving us technology.”
We know what the aliens want in return - human flesh!
How about some one working on EYE GLASSES optics? Technology is archaic by today’s standards. As are Refraction’s. They get close to mine, but can NEVER get it right. I keep telling them the letters are blurred not clean or crisp.
Well, that’s what happens when you don’t focus on your job.
What could possibly go wrong?
The pickle slicer was old?
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