FP: Hugo Perez and Tania Cortez

A WAV file transmitted (message) over a ray of light (medium)

Objective

Transmit sound from a WAV file using a laser beam as the medium.

Assignment Overview

  • This project utilizes a laser beam to modulate and transmit sound derived from a WAV file. The sound is then decoded back using a solar cell. Success is determined by accurately transmitting and reconstructing the sound from the toy telephone recording.

Selected Message and Medium

  • Message: Audio from a WAV file containing recordings from a toy telephone
  • Medium: Ray of light (laser)

Project Steps

1. Encoding Process

  • Describe the Encoding Method:
    • Use an audio source to produce sound (in this case, a WAV file).
    • Connect the audio source to an audio transformer, which modulates the laser's output with the audio signal.
    • The laser beam is modulated by varying its intensity according to the audio signal.

2. Transmission

  • Medium Details:
    • A continuous laser beam serves as the transmission medium, carrying the modulated sound.
    • The laser is pointed at a solar cell positioned at the receiving end.

3. Decoding Process

  • Describe the Decoding Method:
    • The solar cell receives the modulated laser beam and converts the light signal back into an electrical signal that represents sound.
    • The signal is output through a speaker, reproducing the original sound from the WAV file.

Challenges and Solutions

  • Challenges Encountered:
    • Precise alignment of the laser with the solar cell for effective signal transmission.
    • Minimizing interference from ambient light sources on the solar cell.
  • Solutions Implemented:
    • Shielding the solar cell from external light to ensure it only detects the laser beam.
    • Careful setup and alignment to maintain a stable laser path to the receiver.

Evaluation

  • Accuracy Assessment:
    • Assess the fidelity of the transmitted sound by comparing the played-back audio to the original WAV file recordings, ensuring minimal distortion or loss of sound quality.

Reflection

  • Lessons Learned:
    • Insights into optical communication, including how laser intensity modulation can be used for sound transmission.
    • Understanding of how different light sources and elements, like the solar cell, can be repurposed for communication.
  • Improvement Ideas:
    • Explore using different laser wavelengths or alternative receiving sensors for enhanced transmission fidelity and range.