Optical Wireless Communications - Visible CommunicationsZabih (Fary) Ghassemlooy Solid state light emitting diodes (LEDs) and organic LEDs (OLED) as well as organic photodiodes are seen as the next generation of general illumination sources, set to replace existing fluorescent and incandescent lamps offering much higher efficiency, longer life span and much lower power consumption. Commercial companies are already offering the first generation LED replacement lamps with standard fixings available in high-street stores. In addition to lighting applications, the visible light spectrum can be used for indoor as well as outdoor wireless data communications, i.e. visible light communications. Visible light LEDs and OLEDs can be switched at sub-micro-seconds rate, which is too fast for the human eye to react but not for a special sensor on our portable digital devices. Thus, opening the way for dual use of visible light sources for illumination and data communications in homes, offices, cars, airplane, trains, etc. |