As a community system, there are two parts common in any discussion on communication.
- Transmitter and 2. Receiver.
These are the two major parts of a communication system. From the perspective of Laser Communication System, we have the same parts but the devices that in use will definitely be different from other communication systems.
The two parts used in Laser Communication System are Photo-resistor and Laser, in which Laser serves as the transmitter and Photo-resistor as a receiver
On a general note, Lasers is very dangerous, as the weakcode beam can cause permanent blindness to the eyes, so those working with Laser must protect themselves and be cautious not to position the beam directly to the eyes because it can damage the eyes in a second. For Personal Protective Equipment (PPE), it is advisable to make use of Laser google in a laser lab, the laser google must be at a frequency of the laser beam production.
What is Laser Communication System?
From my recent post, I explain what Laser Communication System is. According to Wikipedia laser is simply a device which emits light by means of optical amplification which based on the emission stimulation by electromagnetic radiation (Heat/Solar).
This system transmits a sound signal via a laser beam.
Wikipedia Laser Beam
To know how it works we need to have the knowledge of devices in use.
IC LM386, 9V battery, laser diode, transistor, photoresistor, capacitor,
The working principle of laser communication system follows this process. A sound signal which is the input is been transmitter through transmitting circuit and laser beam carriers the transmitting signal via laser diode to a receiver circuit to produce an output signal.
The transmitting system involves the signal processing electronics which can be analog or digital, a laser modular and a laser with visible and near-visible wavelength. For the signal processing electronics comes with a laser diode which serves as feedback to ensure consistent output through photodiode therein. In modulation part, there are three which are AM which is easy with a gas laser but hard with a diode. AM connote amplitude modulation. Pulse Width Modulation PWM which is a modulation technique that is used to encode a message into a pulsing signal. PFM (Pulse Frequency Modulation) the potential highest bandwidth usually less than 100kHz.
With the above mentioned we have the transmitting system/circuit.
The receiver system comprises of telescope which the antenna, signal processor, and a detector. The detector in receiver system consists of Pin diodes, an avalanche photodiode, and single and multiple detectors. Here, receiver and transmitter are included because after it receives the signal from transmitter system via the beam the receiver system transmitter and releases to become output signal.
Why do we consider Laser Communication?
The application of Laser communication begins when there is a need for high-bandwidth communication and imagery. This communication system is like a speed of light. In the discovery, the laser can be used to transmit satellite to satellite, terrestrial to the airplane, terrestrial to satellite
The use if the laser cannot be overemphasized when discussion about submarines, avionics and military system. If we look at radio wave and laser communication, the laser is better than radio communication. The packing of light wavelengths to sound waves is tighter and the light waves are transmitted with a stronger signal per second.
Laser Communication is been considered for 100 times bandwidth to RF (Radio Frequency). Due to the fact that the power is directed to a target, the transmission power required less much power with less much power loss. In Laser communication, we barely see the antenna because of the size. The antenna is very small to RF antenna.
Application of Laser Community System
Laser System Mounted in a Turret Attached to Airplane Nose
If you have been following the review, some application already been mentioned. A list of laser communication system are:
Mass Communication: 400TV Channels and >40,000 phone conversation.
Communication across the runway in Airport made easy with Laser Communication System.
Is beinh used in defence and sensitive area
Satellite to Satellite and Earth to Satellite.
In conclusion, Laser Communication System technology has not yet mature. Many application of Laser is still improving and new projects and techniques to improve this communication system are still in works. One of this future consideration is beam combination in which several beam streams are blend together into one high power beam. Remember never direct laser beam straight to the eyes, it can cause permanent blindness.
Thanks for reading.
References
https://www.allaboutcircuits.com/projects/build-a-laser-communication-system/
https://people.ece.cornell.edu/land/courses/ece4760/FinalProjects/s2003/kmc29/index.htm
https://electronicsforu.com/electronics-projects/hardware-diy/laser-communication-system