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Electronically Change Material Refractive Index

  1. Jan 16, 2017 #1

    How do I electronically change material refractive index? Is Kerr effect the right way? Is there any good material that have Kerr effect, that can be used in modern gadgets? Is there any gadget/device that use this kind of material?


  2. jcsd
  3. Jan 16, 2017 #2


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  4. Jan 16, 2017 #3

    jim hardy

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    I had a brief encounter with a GE Talaria projector , one of the more amazing gizmos i ever encountered.
    It modulates the shape of an oil film to make an adjustable lens for projecting TV signal on to a huge screen.
  5. Jan 16, 2017 #4


    Staff: Mentor

    GE had a knack for making amazing things that remained rather obscure. I had the privilege of working several years underneath the sign in the video below. It was controlled by a magnetic amplifier. GE made exciters using magnetic amplifiers but many engineers have never heard of them.

    The lights on the sign were ordinary incandescent light bulbs. The secret of the sign that we GE engineers knew about was that there were two signs at opposite ends of the park, and that the magnetic amplifier controlled them so that the pair drew constant total power even though the lights went off/on. That was a good trick in the 1920s or 30s when it went up without relays or moving parts. I suspect that the sign is replaced with LEDs today.

    The GE sign's rival for fame was the RCA Victor "His Master's Voice" dog 20 miles down the road in Albany.

  6. Jan 16, 2017 #5


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    As fascinating as magnetic amplifiers are, we need to get back to the topic of voltage controlled RI ...
    Grheee: What are you really trying to do here that needs a variable RI ?
    Do you want to change a focal length, refraction angle, or maybe modulate the polarisation of light ?
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