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Collimating Semiconductor Lasers Without Lenses
An anonymous reader writes "Researchers at Harvard University and Hamamatsu Photonics have found a way to collimate lasers without lenses. In the new 'plasmonic collimator' technique, grooves are etched directly into the semiconductor laser's internal mirror. This results in surface plasmons giving rise to constructive interference, eliminating the need for the bulky optical lenses that usually focus the light from semiconductor lasers. The technique has promise for steering laser beams without moving parts and for working with polarized light."
no sharks?
Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
But can you hammer a 6 inch spike through a board with your penis?
I don't know much of anything about physics research. Here in biology, if any aspect of your research has applications to cancer, you talk that connection up, even if it's somewhat tenous. There's a glut of funding available for cancer wheras there's substantially less for equally important medical research on aspects of biology "lay people" don't understand. A lot of research funded with cancer research money really has very little chance of actually taking steps towards curing cancer (which is not to say we shouldn't be funding those projects.)
Is "homeland security" the equivalent of that for physics research? Show a link as to how your project might be used to prevent terrorism and you'll get a blank check from the government? I sincerely hope so, at least some good can come out of our paranoia.
The researchers claimed that if they can achieve a fully collimated laser, it will lower the cost of communications lasers by eliminating the need for lenses while enabling long-range chemical sensing. The latter could be used for homeland security and environmental monitoring applications.
I don't remember laser sensors being a pressing need for defense of the motherland. Am I downplaying the risks here? I can only imagine that cheaper components will make total surveillance even easier.
I guess this kind of advancement could give birth to disc-sized BluRay or DVD readers, since it is probably, along with the DC motor, the biggest moving part in a DVD assembly... Good for the laptop and ultraportable industry!
...the shark jumps you!
Sweeeet! Shark sex!
We didn't have solid state lasers, you had to bring your own tank of CO2 and a Xenon flash lamp to get the thing pumping. You had to adjust your mirrors with a micrometer. muttering to myself... "damn smartass kids" as I wander across the room to get my Geritol.
"Researchers at Harvard University and Hamamatsu Photonics have found a way to collimate lasers without lenses. In the new 'plasmonic collimator' technique, grooves are etched directly into the semiconductor laser's internal mirror. This results in surface plasmons giving rise to constructive interference, eliminating the need for the bulky optical lenses that usually focus the light from semiconductor lasers. The technique has promise for steering laser beams without moving parts and for working with polarized light."
Translation for people like me: Smart dudes at the #1 school and a lab with lots of funding and laserbeams found a way to fire said laserbeams by shaping the mirror instead of having a flat mirror and firing it through a shaping lense. This is good 'cuz now they will be able to do stuff they had a hard time doing before.
But that is with a lens. What they are doing is with plasma. So it can be controlled without moving parts. In theory with that you have a program that follows your eyes. then using these lasers they can shine the image and hit the right cells for realistic holodeck like images.
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
I'm a little curious... TFA didn't really clear this up much. It sounds like they've managed to focus the laser without needing a lens, which is definitely geeky enough to warrant notice... good stuffs like "interfere constructively" and "plasmonic collimator effect" are always fun.
I am a little bit perplexed, though. They're apparently using etched grooves to induce electromagnetic interference which results in better polarization/linearity of the emitted light. What I don't understand is how this could be used to electronically "steer" the beam. It sounds to me like it can only be used to point the beam in one static direction. The article mentioned a "spatial emission pattern", but I'm really not sure what that means in English...
They seem to be excited over the fact that no moving parts are involved, which also puzzles me. The lens in a stationary laser isn't a moving part, and it sounds like they've found a technology that replaces the lens. A laser that could be aimed, though, required moving lenses/mirrors... returning to my original question, I'm curious how they're going to "steer" the laser without moving parts.
Finally, I'm really not sure what they mean by this statement:
The researchers plan to etch concentric circular grooves in an attempt to fully collimate the laser beam in all directions.
Isn't that kind of contradictory? Like saying "we intend to fully polarize the light in all directions"? You can't have partially polarized light, and you can't have partially collimated rays... that's like saying you have somewhat parallel lines or a slightly rectangular square...
Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
I didn't RTF because... "plasmons"?
Sounds fishy to me. Sounds like something a Jedi Knight uses.
Ever since I watched Star Wars for the first time, I had this idea: if I could rapidly move common focal point of thousands of tiny laser beams along the fixed segment of handle axis, with constructive interference (mostly) sustained, with lasers' wavelength matched to a line of absorptive spectrum of atmospheric gas (on Earth it would be nitrogen), I would have a plasma weapon (or tool) very much resembling a lightsaber.
It should also have adaptive (microcomputer controlled) focusing, so that if any obstacle enters the "blade" segment, all the lasers immediately keep focus on the point of contact, to make it yield to blade as fast as possible
Now, there is a way to it. I imagined some piezoelectric-actuated mirrors would do, but had no idea how to construct it. This new thingy is so much better and more fine-grained.
Dear PPH,
I am a scientist on the team mentioned in the article and I just wanted to say that you, sir, have rocked my world! I just went down to the mall after reading your comment, and bought one of these "laser pointing" devices. And holy shit, you were totally right! There is absolutley nothing unique or different with the research I've spent 7 years of my life on. This cheap $10 plastic toy is exactly the same thing as an laser built into an IC without a lense or moving parts. EXACTLY the same. I mean, they're both totally like lasers right? Mind. Fucking. Blown. Anyways, the guy that sold me the device is keeping quiet in exchange for top billing on the article in Science, and a piece of the sweet sweet Nobel prize money.
Anyways, next up for me is taking the $10 plastic toy (because, after all, my research is completely useless as you've pointed out) and integrating it into a quantum computer. Refocusing the laser at quantum scales at the speed required to run a quantum computer can easily be achieved by swapping plastic tips on the end of the pointer (a process we've dubbed "rejiggering the doohickey" in science speak).
Thanks, and God Bless for pointing out the errors of my way. Guess I need to spend less time in the lab and more time in the mall!
Sincerely yours,
Prof. T. Barnum Humperdink III
Now all we need is a large spinning mirror...
You sir, owe me a new keyboard!
Posts like that should come with a "Do not read this while drinking" warning.
Exactly which part of “steering laser beams without moving parts” escaped your understanding?
Guess what I got in Google:
A dog's wife.
So this about frikkin' dogs with frikkin' wives with frikkin' laser beams attached to their heads?
Help a man when he is in trouble and he will remember you when he is in trouble again.
Wikipedia says... er, actually no, it doesn't. The only mention I could find of the word "Sex" in its article about sharks is an occurance of ASEXUAL reproduction (i.e., virgin birth).
It only mentioned the "Jesus Shark". Fish generally don't copulate like mammals, but instead the female lays eggs and the male then ejaculates on the eggs. I'm not sure if sharks reproduce like this, but if so, well, if the shark jumps you you will get laid -- TO REST.
I think the goatse site has an article about bestiality with a dolphin. But no sharks.
Or lasers.
mcgrew's razor: Never attribute to stupidity that which can be explained by greedy self-interest
That has to be the most informative article ever containing the word goatse.
0xB315AA8D852DCD3F3DCA578FD2E0BF88
Translation: instead of a conventional curved lens, they use a fresnel lens. This allows them to carve the lens directly into the laser, make it flat, and possibly tune it.
You're at slashdot, where occasionally you're going to run into some articles that are writen at a postgraduate level instead of the eighth grade level sanity would logically insist on.
I once read a paper that used the word "enumerate" five times in a single paragraph, and didn't once use the word "count". The submitter could have communicated rather than obfuscated, but then he wouldn't have looked so smart.
The secret to reading postgrad level writing is look up any words you don't understand. The when you're done reading, read it again.
mcgrew's razor: Never attribute to stupidity that which can be explained by greedy self-interest