How does Li-Fi work?

How is a Li-Fi based system designed?

A Li-Fi system is built primarily with these four sub-components: A bulb, a Radio Frequency Power Amplifier (RFPA), a Printed Circuit Board (PCB), and an Enclosure. The center of a Li-Fi system is based on the sub-assembly of a bulb, which is inserted in  a dialectric material. The Printed Circuit Board (PCB) controls every electric signal of the lamp and contains a microcontroller that manages the different functions of the lamp. The Radio Frequency Power Amplifier Circuit (RFPA)  generates a radio frequency signal which is later converted into an electric field.

The dialectric material has two functions: on the one hand, it acts as a waveguide for the radio frequency energy radiated by the Power Amplifier; and on the other hand, it also helps concentrating the electric field by focusing the energy in the bulb. All the components are contained in an aluminum enclosure. The whole system works because the concentration of energy in the electric field is transformed into plasma which in turn produces high-intensity beam of light.

The transmission of data is done by modulating the intensity of the light. The modulated light signal is then received by a photo-sensitive detector, which then converts it into electronic form. This modulation is performed in such a way that it is not perceptible to the human eye. Li-Fi transmits binary data in the form of light pulses and it relies on Optical Wireless Communication (OWC) technology, thus dispensing with cables or optical fibers. Li-Fi can cover up to three meters distance wise.