Transmitting and Receiving Ultrasound Wave Based on Laser Light

Abstract

Our project was divided into two distinct sections, circuit transmitting and receiving ultrasound Wave Based on Laser Light. A Wien Bridge and a Triangle Wave Oscillators used to obtain a sine and a triangular wave, respectively. A comparator circuit which produces Pulse Width Modulation (PWM) that has the same frequency for triangle wave. The PWM was used to drive laser diode that produced laser light through by MOSFET transistor and received this light by receiving circuit which consists of a photodiode with resistor as a voltage divider, amplifier circuit to amplify the signal and filter to get any desired frequency. The main objective of this project primarily was to realize a transmission-reception system to transfer ultrasound Frequency via Laser without a guiding medium, using modulation with little quality loss.