1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Audio signals transferred by a light source

  1. Sep 11, 2011 #1
    Hi, I am currently working on a little science project, I came across this page about sending audio signals through a laser pointer.

    http://www.i-hacked.com/content/view/162/44/ [Broken]

    I was wondering if it is possible if I did it with an ordinary light bulb.

    It said that the data is transferred by the light's amplitude, so if I were to use a light bulb instead of a laser point, does it kind of mess up the signal if I were to stand closer or farther from the receiver? Or does the audio output on the receiver will just have a lower volume if I stand farther away?

    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Sep 12, 2011 #2
    The problem with an incandescent light bulb is that it's response time is slow and may not accurately transmit higher frequency sound waves, But it's not impossible. I remember seeing a project for what you are describing using light bulbs when I was a kid. You could also do it with LEDs.
  4. Sep 12, 2011 #3
    LEDs would seem to be the closest thing I have in mind.

    But will the distance of the light and the receiver change the volume?
  5. Sep 12, 2011 #4
    No, The distance shouldn't affect the volume (provided the device you are using is dependent upon luminosity for volume) if you have a true laser... because the luminosity would be relatively constant... no diffusion, but if you are using an incandescent bulb or LED then yes distance will affect the volume.
  6. Sep 12, 2011 #5
    Oooh, i get it.

    That's exactly the effect that I was hoping for.

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook