QUARTER II : 2019

TECHNICAL ARTICLE

Light- The technology of the future

There was a time when you used to believe that light was divine and that only the sun could produce it. Humans later discovered fire which busted the fact that the sun was the sole emitter of light. In the 18t​h century, Thomas Alva Edison did a path-breaking invention- ​the light bulb. ​That was not enough to change people’s notions. But that invention changed man’s perception of light and energy. After the invention of the alternator, producing electricity was not more a herculean task. The electricity was mainly used for lighting purpose.. It was the works of Maxwell and Einstein that put forward the idea of using a light source to eject electrons from a metal which clearly shows that light is not that just gives us energy.
In 1840s John Tyndall a scientist observed a phenomenon named ​Tyndall effect​, where tiny particles in a fluid can scatter light. Later on he explained the theory of Total Internal Reflection which lead to a new device name Optical Fibre which was discovered in 1926.

- Optical Fibres

As the name suggests, are thin strands of silicon which transmit light. Being an EM wave, it faces no issues of external interference and is a high-speed method of communication which is replacing twisted pair cables and coaxial cables.
Later came a totally new concept of ​Solid-State Lighting​. A light which is produced by Solid State or Semiconductor devices like ​Light-emitting Diode​. This was much more efficient than traditional methods. This technology gave rise to a totally new branch of Physics named Photonics. ​Photonics is a subject that deals with production, manipulation and understanding the use of light.
Giving LEDs a boost came the invention of ​LASERs in the 1960s. They are of three types- Ruby laser, Helium-Neon Laser and the Semiconductor laser. LASERs are now used in various places like biomedical, optical communication, understanding patterns of light, interference and diffraction, etc.
Now, the solid state physics has so much improved that we have tons of devices which emit and detect light like phototransistors, LDR, photodiodes, APD, solar cell etc.

- LiFi

The real innovation of this century is the LiFi, which is often compared to the word WiFi. LiFi is the abbreviation for Light Fidelity. ​It is more efficient, faster and more effective than the traditional methods of communication.
As per the theory, any light source can be used for communication. But the technology we have has not been up to that mark that we can harness it directly. Now we use small models of LiFi like with an LED and an LDR through Arduino programming to learn and understand it better. The instruction which is sent from a computer is converted to binary, which is again converted to on and off of an LED. This is detected by the Light dependent resistor LDR which converts light to electronic pulses so that computer can decode them. This is basically of the system works on a small scale. For expanding this technology, we need to make it more affordable and also expand the infrastructure because, It is an undisputed fact that LiFi will march the way forward for the future of internet communication.
There are also a lot of innovations like ​blue LED and ​OLED ​which are known to be the future of photonics and the heart of the modern industry. Light is an immense source of energy. The technology can be used in a lot more ways which can exploit this resource to its full potential. We also should understand that it's we, the engineers who should strive hard to make this possible.