An optical transmitter/receiver system for wireless voice communication

The design of an optical transmitter/receiver system, suitable as an educational project for the demonstration of low-noise wireless voice communication in the laboratory, is described. The system, having a range in excess of 8 m, uses a VCO (voltage-controlled oscillator), operating at the center frequency of 100 kHz, to achieve voice data encoding. Optical decoding at the receiver is performed using a conventional phase-locked loop (PLL) circuit. As an optoelectronics design project, the system successfully integrates the concepts of free-space optical communication, frequency modulation, and analog electronics design, which are common to infrared (IR) remote control devices