JLD College of Engineering & Management

LASER TORCH BASED VOICE COMMUNICATION

SYSTEM

SOURAV DAS - D16005400633008ARIJIT SIKDER - D16005400633002MITALI MONDAL - D16005400633011

PROJECT TEAM

INTRODUCTION Our final year project is based on the concept of laser (Light Amplification by Stimulated Emission of Radiation) for transmitting analog signals. We have used phototransistor to receive the signal at receiver. Laser as a communication medium can provide a good substitute for the present day. Laser communications offers a viable alternative to RF Communications for inter satellite links and other applications where high performance links are a necessity. High data rate, small antenna size, narrow beam divergence, and a narrow field of view are characteristics of laser communications that offer a number of potential advantages for system design. For voice transmission amplitude modulation of laser pulse was used to transmit the voice signal. Condenser microphone (acts as a transducer) converts the voice into electric pulse which was then amplified and transmitted through laser. Photo detector at receiver detects the laser light and voice output through loud speaker.

OBJECTIVES OF PROJECT

The main aim of this paper is to construct a Laser communication system by using low cost laser torch and available electronic equipment which can be got easily form local electronics shop everywhere and people can construct for their personal use.

• To implement light based voice transmission and reception system by using light from a Laser-torch as the carrier of the signal.

• To reduce the complexity for communication in the places where optical fiber or any wired communication is very difficult and expensive.

APPLICATION OF PROJECT

1. Using this circuit we can communicate with our neighbors wirelessly.

2. It can be used in inaccessible areas.

3. In future it can be commissioned in satellites for communication.

4. It can be used in conference halls.

BLOCK DIAGRAM

CIRCUIT DIAGRAMTRANSMITTER

CIRCUIT DIAGRAM RECEIVER

PROJECT PICTURES Transmitter RECEIVER

PROJECT PICTURESCOMPLETE PROJECT ASSMBLING

Limitation 1.The factors such as beam dispersion, background light, shadowing, rain, fog, snow, pollution, smog causes an attenuated received signal and lead to higher bit error rates.

2. Limited up to the range of 500m.

3. For longer distance communication high power laser is required which is costly.

Future Enhancement

1. Multiple voice, data, picture, video can be multiplied simultaneously to perform communication using Multiplexer.

2. Half duplex or even full duplex communication can be achieved by software implementation .

3. A more power laser can be used to increase the range of communication. 4. Laser can be replaced by IR laser that can’t be visible by bare eye.

THANKING YOU