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Thread: Physics question: interference pattern?

  1. #11
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    WOW! That is really cool Robin!! Looks like I've got a new experiment to try out
    LASERS!!

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  2. #12
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    Internal reflections and interaction between front and back surface of the given medium perhaps?
    Quote: "There is a theory which states that if ever, for any reason, anyone discovers what exactly the Universe is for and why it is here it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another that states that this has already happened.”... Douglas Adams 1952 - 2001

  3. #13
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    I agree with Steve; it is a combination of refraction and interference. Pretty colors!
    Phil Bergeron( AKA 142laser)

  4. #14
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    Default poor man's collimation tester

    seems like 4 years is a good amount of time to bump a thread that seems relevant to what I am searching

    given that shearing interferometers from thor, Edmund, Newport and the likes are a tad expensive, has anybody come up with a way to use interference patterns to collimate laser diodes?

    shearing? Michelson? other diy method?
    I am basically looking for the poor man's collimation tester as an alternative to running back an forth in the room with Vernier calipers...

    possible?
    "its called character briggs..."

  5. #15
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    I believe those fringes are the result of diffraction off edges the beam encounters as it goes through the system. Edges of mirrors, apertures, or on the lumia generators. Not fringes made by interference.

  6. #16
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    When collimating without a shear plate, I use a monocular to see the target across the room. Draw the intended diameter circle on a black card and tape it to the wall, or use a white card and alignment goggles. Get it as far away as possible, so you can easily see the target in the telescope.

  7. #17
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    I believe so, too. Even if it was interference it is too random coming off a lumia disc to have any meaningful use.

    that's why I am asking on any sort of diy collimation tester methodology
    "its called character briggs..."

  8. #18
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    Quote Originally Posted by Eidetic View Post
    When collimating without a shear plate, I use a monocular to see the target across the room. Draw the intended diameter circle on a black card and tape it to the wall, or use a white card and alignment goggles. Get it as far away as possible, so you can easily see the target in the telescope.
    a cosmetics magnification mirror can also be a workaround if the distance is not available.

    however, a self made interferometer would be a really cool toy!
    "its called character briggs..."

  9. #19
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    Shoot a PM to DanielBriggs here on the forum... I think he hacked something together along the lines of what you're thinking of, but it was years ago. Maybe he can post here with what he worked out.

    Adam

  10. #20
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    Quote Originally Posted by buffo View Post
    Shoot a PM to DanielBriggs here on the forum... I think he hacked something together along the lines of what you're thinking of, but it was years ago. Maybe he can post here with what he worked out.

    Adam
    yes, i seem to recall the same.

    the problem with dan's "quick hacks" is that they usually involve robotic arms and high spec machinery

    I'll see what I can find and report back
    "its called character briggs..."

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