Final Proposal: Laser Communicator

Purpose:

The objective of this project is to build a laser communicator which transfers sound signals from a microphone to an amplified speaker via a laser beam. In this project, the synchronization of light with the input and output sound and the effects of the amplitude of the sound waves on power and intensity of the light will be analyzed.

Proposed Design:

The laser communicator will include two sets of devices: an input and an output. In the input set of devices, a dynamic microphone, a transistor, a three cells battery holder, and a 4.5V laser pointer will be connected together. As for the receiver, a 2V solar cell will be connected to an amplified speaker. The input will be powered by the 4.5V battery which contains three 1.5V battery cells. When the sound is input via the microphone, the microphone will induce current to send these sound signals as audio signals to the transistor. This will induce current at one terminal of the transistor, and this terminal will send signals to another terminal to control the flow of these signals. When these electrical signals reach the laser pointer, the laser pointer will transfer these signals through a laser beam to the solar cell. This process will work this way. When photons of enough energy from the laser beam strike the semiconductor on the solar cell, electrons will start to loose from their orbits and will begin to flow in a certain direction. This will create a current, and this current will be generated depending on the intensity of the laser beam. Then this current will flow from the solar cell to the speaker. As a final stage, the speaker will convert these electrical signals to sound waves so that the input sound will be heard from the speaker. This design is explained by an accompanying sketch.

Criteria for Success
    In order to success in this project, we have assigned tasks to each person and we have set the due dates to finish everything on time. We have also prepared the needed materials for this project and have discussed what will be done to achieve our expectations of this project. 
We expect to accomplish a laser communicator that can amplify the input sound without direct connection between the input and output set of devices. We expect that the light produced by the laser beam will synchronize with the input and output sound waves. This will be done by recording data of the input and output sound waves and constructing a graph of the sound waves created by input vs. output. In addition, we expect that the intensity of the light produced by the laser beam will be proportional to the square of the amplitude of the input sound waves. In order to obtain this, we will use the graphs of input and output sound waves and will record the current flow through the input device using the multimeter. Lastly, we have also started to review about programming to build a computational model which will depict light transferring signals to the solar cell.

Tasks
4/17-Yileen-Final proposal
4/19-Emily-Making sure of needed materials
4/23-Joyce-Buy materials
4/29-Build input: 1. Yileen-microphone and transistor
                   2. Emily-battery and laser(4.5V---may vary depends on the laser pointer we                     use)
                       - test the voltage of the laser pointer
                 output: Joyce-solar cell and the amplified speaker
4/29-Testing: if the sound is transferred by the laser pointer from the microphone to the amplifier
5/04-Modify if needed
5/11-Collecting Data: 1.record sound frequencies and amplitudes using loggerpro
            2.measure current and resistance using multimeter
5/11-Analyze: 1. Emily-Calculate power (i^2R, i=current, R= resistance)
                                   and intensity (I=P/A, A=area of the solar panel)
        2. Joyce-Graph frequency of input vs frequency of output
        3. Yileen-Graph Intensity of light vs. Amplitude of sound
-Programming: 1. Construct computational model with laser and solar cell
          2. Construct graphs