'Cloaking' idea traps a rainbow (electric, material, physics, cameras)
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"Researchers have trapped a rainbow - slowing light to a near-stop - in an array of 25,000 "invisibility cloaks", each smaller than a hair's breadth.
A report in the New Journal of Physics shows how the quest for an invisibility cloak is leading to cleverer ways to use and manipulate light."
They need to caption that video. I understood about 10% of what she said so I'm lost....
Me too, i was hoping it would generate some debate so i could try and work out what it all means. I was grappling with the theory and nearly grasped it (in a very basic sense) then it just flew past me and hit the wall...
Hello, my name is Vera Smolyaninova. I'm a professor of physics at Towson University. I will tell you about our latest look on electromagnetic cloaking.
The idea of cloaking is based on so-called "curving" of optical space. Optical properties of materials are characterized by the way they react to external electric and magnetic fields. These properties could be tailored in such a way that light will avoid a particular cloaked region of space. Typically this is done with matter materials.
Recently, we have demonstrated that the same effect may be achieved by much simpler means. When light propagates inside a wave guide, you can literally bend optical wave guide, and achieve the same result. Three years ago, we were able to create a large broadband invisibility cloak. By placing a gold-coated lens on top of a flat gold-coated glass slide. Empty space between the gold surfaces acted as the wave guide we need. The area around the point of contact was cloaked. Light rays propagated around this area.
Now we have extended this look by making tens of thousands of cloaks arrayed in a periodic fashion. Instead of a large single lens, we use the micro lens array. Normally these devices are used in CCD cameras and multi-channel sensors.
In our evoke[?] we have coated the micro lens array with a thin layer of gold and placed it on a gold-coated glass slide. Instead of just one cloak, now we have made tens of thousands of cloaks simultaneously. All these cloaks in the array operate just like the individual cloaks studied earlier, but now we are able to study how all these cloaks may interfere with each other when they are forced into close proximity.
Simple symmetry consideration indicates that arrays of slightly imperfect cloaks, which work well enough individually, will start to scatter lots of light when illuminated at some arbitrary angle. This behavior has become very clear in our experience. Thus, we have demonstrated a very sensitive way to test cloak quality, which could become useful in the future.
Those of us with a hearing loss that can't understand anyone with an accent appreciate that "translation". It's frustrating as all get out to not be able to discern the sounds and turn them into words.
When I used to call for tech support and I'd get someone in India it was terrible. If they happened to be someone that talked fast all I heard when they spoke a sentence was one long sound. No words, just sound.
Those of us with a hearing loss that can't understand anyone with an accent appreciate that "translation". It's frustrating as all get out to not be able to discern the sounds and turn them into words.
When I used to call for tech support and I'd get someone in India it was terrible. If they happened to be someone that talked fast all I heard when they spoke a sentence was one long sound. No words, just sound.
In relation to your post (but not the thread) in the UK you have the legal right to request to speak to someone for whom English is the first language. It's one of those "Really? I didn't know that!" laws that's been in place since the 90s.
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