Laser Communications

How it works



The Transmitter involves a signal processing circuit, and a laser. A laser diode is used to create the laser signal. Laser Diodes include Photodiodes for feedback to insure consistent output.


This is the "Antenna" of the system. The Receiver involves a Signal Processor and Detector (Some kind of Photodiode) that will capture and read the incoming laser signal. Often both ends of a laser communication system will be equipped with a receiver and transmitter


Thus system is set up to send voice data. In this example, a person's voice gets put into a conditioning circuit so that the full eight bit range of the analogue to digital converter is utilized. 

Once the digital signal is obtained by the ADC, the MCU passes the signal to the UART. The UART sets a 

transmit pin high or low according to the serial protocol. Some conditioning is applied to this signal as well in order to ensure constant current to the laser.
On the receiver side, the signal is read by a photo transistor and basically the signal goes through an opposite sequence to output a sound instead of receiving one and using the DAC will change the digital signal to an analog one.