Music Throughout a Laser!




About: Designer, gamer, dreamer, and scientist.

Transmitting information through a beam of light may seem strange but it is plausible. This instructables is about how to transmit music through a laser from a mobile device to the speakers. This project was carried out with the purpose of carrying out scientific dissemination and bringing the field of optics to the general public in my country and the help of some international institutions (OSA and SPIE). After many attempts to find a project that we liked, we decided on this because it has perfect qualities for disclosure: easy transfer of the components, fun and interactive, visibility of electromagnetic radiation.

For more than 3 hours we were riding this circuit. In this tutorial I will show you how to make this amazing demonstration for both children and adults.

Step 1: Tools

We need the following tools for assembly:

  • Speaker plug
  • Laser diode or laser pointer
  • Speakers
  • Cellphone, mobile, Ipod, etc
  • Plug (We can use batteries)
  • Cables bridges with crocodile clips
  • Photodetector or Photosensor
  • Amplifier or electronic amplifier (optional)
  • Something to support the assembly

Step 2: Connecting and Testing the Laser Diode

First, we take two crocodile clips and at one end of them we connect them to each end of thelaser diodecables. Now, we take the plug and cut the cable until we discover the conductive part of it (copper strands), connect the missing ends of the crocodile clips and verify that it turns on the laser diode.

Step 3: Connecting the Speakers to the Photodetector

We take the photodetector and connect a crocodile cable at each end. To the speakers we cut the connector and peel the cable until we see the copper strands. Finally we connect the ends of the crocodile cables and turn on the horns.


To amplify the signal coming from the photodetector we can connect it first to an amplifier (input) and from the amplifier to the speakers (output).

Step 4: Connecting the Speaker Plug to the Laser and the Cell Phone

Now, with two crocodile cables we make the following connection in the speaker plug (shown in the images).

Now, we connect the crocodile cables of the speaker plug directly to the laser diode and connect the source through the crocodile cables to the speaker plug. Finally, we connect the plug to the cell phone and place the laser at a distance of approximately 1.5 meters from the photodetector, place one support for the laser and another for the photodetector. Point the laser to the photodetector and let the party begin!



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