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Collimating Semiconductor Lasers Without Lenses

Posted by kdawson on from the should-make-somebody-rich dept.

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."

11 of 136 comments (clear)

  1. It may be very cool by BadAnalogyGuy · · Score: 4, Funny

    But can you hammer a 6 inch spike through a board with your penis?

    1. Re:It may be very cool by dgatwood · · Score: 4, Insightful

      Amazing. A reference to a relatively mindless comedy (Austin Powers) gets modded up, while a reference to a really good geek movie (Real Genius) gets modded down as off topic. *sigh* Kids with mod points, I tell ya.... Bets on whether the person who modded the parent down had been born yet when this movie came out? :-)

      --

      Check out my sci-fi/humor trilogy at PatriotsBooks.

  2. Umbrella funding by philspear · · Score: 5, Interesting

    The latter could be used for homeland security and environmental monitoring applications.

    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.

  3. Disc size reader? by courteaudotbiz · · Score: 5, Interesting

    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!

    1. Re:Disc size reader? by gmack · · Score: 4, Insightful

      From the article:The researchers claimed that the plasmonic collimator effect is similar to the way phased-array antennas steer a beam, creating the possibility of steering laser beams with no moving parts.

    2. Re:Disc size reader? by jd · · Score: 4, Informative

      If you can polarize the light, you can have multiple layers distinguished by polarity. Besides, I thought multi-layer systems usually used different frequencies, as optical media work by seeing what reflects and what doesn't. If you add the ability to polarize the light, you can double the number of layers.

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
  4. Back In My Day by Anonymous Coward · · Score: 4, Funny

    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.

  5. Steering laser beams by clone53421 · · Score: 5, Interesting

    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.
    1. Re:Steering laser beams by smaddox · · Score: 4, Informative

      If you know the wavelength of a beam of light, you can use interference effects to direct it. This group's current laser uses parallel etched lines to collimate the beam in the Y direction. By switching to concentric circles, they can collimate the beam in both X and Y directions.

      You CAN have partially polarized light, though. Daylight is partially polarized. If you hold up a linear polarizer to the sky, it will be slightly darker or lighter depending on how you orientate it.

      You can have partially collimated light, too. In fact, you can never have completely collimated light. Light tends to spread out the farther it travels. This is usually attributed to diffraction, but in reality they are both results of the true behavior of light - which is modeled by quantum electrodynamics.

  6. Re:Hologram by badboy_tw2002 · · Score: 5, Funny

    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

  7. Re:Translation: by f8l_0e · · Score: 5, Insightful

    I don't know what's more sad.

    1. Someone dumbing down a tech article for the slashdot crowd to read.

    2. Said post getting modded up as informative.

    Welcome to the new slashdot. Striving to be more like FOX news every day.