Laser Based Communication System.

Laser Based Communication System.

Introduction:- An optical communication system for inter and intra building communications can be built using the following three basic component. A light emitting element.
1. A light emitting element, which could be a laser diode or light emitting diode.
2. Transmission media such as optical fiber cable or free space.
3. A light receiving element, which could employ avalanche photo-diode, PIN photo-diode or any other light sensors like LDR.
Since the communications performance of the system depends on the overall characteristics of the above elements, the characteristics of the individual element should match. Here we present a one way optical communication system using a short wave-length visible laser diode as the light emitter source, free space as the transmission media and a light dependent resistor as the light receiving element. The system is ideal for speech communication between two adjacent offices or between homes on opposite sides of a road. The diagram of the system can be shown as below:-

Speaking person.
Condenser
Mic. Pre- laser Ampli- -fier LS-1

P Display

Rec. N person

Lsp-2

Buzzer