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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.
...the shark jumps you!
Have gnu, will travel.
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!
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.
Is this basically the same effect used by those cheap laser pointers to project cute pictures instead of a simple dot? For $10 I bought such a pointer that included about a dozen interchangeable tips. Each contains a tiny plastic film (a hologram) that shapes the beam into a cute symbol (arrow, smiley face, etc.).
It sounds like what is being proposed is a hologram (basically a kind of diffraction grating) etched directly onto the die surface. Not a bad idea, but not really new. Unless you want to share your Nobel prize with the guy selling cheap junk in the booth at the mall.
Have gnu, will travel.
That's nothing. I just found a way to frabjimate SUPERconductor lasers without lenses.
"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.
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.
I don't see how homeland security and environmental monitoring applications are in any sense incompatible with sharks with freaking laser beams... in fact, both the DHS and the EPA would probably be better off if they had more of those! (I'm pretty sure I'd be worse off, though...)
You see, homeland security will have that tech and therefore, will be able to track it.
As far as EPA is concerned, well, if they find that you're abusing your sharks, they'll come down hard on you! I mean, there are work rules - even for evil geniuses such as yourself. Excuse me, I didn't mean evil, I meant morally and ethically challenged geniuses.
I believe "Surface Plasmons" were either a rock band or the bad guys from a Dr Who episode.
It is by the juice of the coffee bean that thoughts acquire speed, the teeth acquire stains. The stains become a warning
Now all we need is a large spinning mirror...
That summary sounded exactly like the rockwell automation's advertisement.
http://www.youtube.com/watch?v=PtuqjFf7-N4
This results in surface plasmons giving rise to constructive interference...
Surface plasmons... that's what Dillan and Troy used to generate a feedback loop in the Cylons in that episode of Battlestar Galactica 1980.
When our name is on the back of your car, we're behind you all the way!
I was JUST wondering how I could possibly Collimate Semiconductor Lasers Without Lenses. And now, I know.
Exactly which part of “steering laser beams without moving parts” escaped your understanding?
You can achieve the same effect by inverting a lateral undefined cloud. If we use the inertial containment nacelle to align it with the primary undefined coil, then by modifying this cargo flux bay, we can make it work in conjunction with the acute plasma procedure. I believe that this will increase the efficiency of the primary deflector undefined by 16 percent. Thus reducing the load on the optical isolinear plate.
Hey, makes about as much sense as the article's existing intro blurb.
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.
because this might greatly simplify beam combination and steering. A 100 x 100 array of 10 watt lasers (total size, say, ~ 2 ft. on a side) would give a 100KW beam in the far field, steerable at electronic speeds. Yeah, dumping the heat will be problematic, but that's what diamond heat conduction components are for.
When focusing a laser through a lens, some of the energy in that laser must inevitably be lost due to the lens not being %100 transparent (invisible). I wonder just how much energy is lost in the lens?
FOXTROT UNIFORM CHARLIE KILO
Well, my first thought was "bad news for Nikon"
That, plus the possible development of various "bug eye" type non-lensed photography methods could be bad news for the long-term viability of lens manufacturers. It may be sort of like Kodak in the early 90's- the vast majority of their profits came from film, and it was obvious film was rapidly heading towards obsolescence. The verdict's certainly not in yet on lenses the way it was on film. But what do you do, if you're a giant, successful corporation, but it's clear you're basically a modern-day buggy manufacturer; your primary market and core competency as a company may become obsolete.
Can anyone tell me how to set my sig on Slashdot?
A curved mirror to replace a lens?
What will they think of next?
I welcome our new plasmonic collimator overlasers!
Going on means going far
Going far means returning
... has to clean it up.
William of Ockham had no beard. The most likely explanation is that it was chewed off by squirrels every morning.
So you say they're grooving their rod.... wait what were they doing?
They ARE out to get you simply because They are in it for themselves and they don't care about you.
Can it be done by physically extending out a structure from the handle that would magnetically confine the plasma?
- Would absorb/vaporize incoming energy or projectile weapons.
- Reduces the amount of power needed to maintain the plasma.
- Terminates the beam to a particular length
- If both sabers had the same polarity they would tend to bounce of each others magnetic fields.
What am I missing?
They ARE out to get you simply because They are in it for themselves and they don't care about you.
I'm no expert on plasmonic collimators, or spintronics, but it sounds a little bit like they've just re-invented the refraction grating.
Well maybe you should spend more time learning Optics and less time picking on informative posts.
What the parent poster was saying is that the "brilliant" scientists, took a mirror and turned it into a mirrored fresnel lens (i.e. a flat lens). So the laser isn't exactly without a lens, they just incorporated the lens into the mirror.
Also, I've built lasers and the lenses used in lasers aren't what I'd call bulky. After all you can buy focused lasers that fit on key rings. I've built one using a bullet shell casing. I'm sorry, but this "amazing" advance isn't all that.
It's a bit novel and I give them credit for thinking creatively, but a collimated beam such as this is likely to have some odd harmonics at distance, and likley to have null spots or rings or lines. Not something I'd recommend for a high power system doing holography.
Typically this is the trend isn't it?
Collimating Semiconductor Laser Lens Workers will find themselves out of a job. Many will be forced into retirement, some retrenched and a few having to retrain to something like a Semiconductor Laser's Internal Mirror Groove Etcher instead; which is probably exacting and difficult manual labour.
I mean they already are being teased by other departments aren't they? being called "Collie Maters"
Geez! I already feel sorry for them.
Don't be apathetic. Procrastinate!
Could this be one of the first steps for the death star?
Those who live by the sword, get shot by those who live by the gun...
Dynamite with a LASER BEAM!!!