Visible light is used in communication systems through a technology called Visible Light Communication (VLC), which transmits data using light signals in the visible spectrum (wavelengths between 400 to 700 nanometers).
🔹 How It Works:
- Light Source (Transmitter):
- LEDs or lasers rapidly blink on and off (too fast for the human eye to notice) to encode digital data (0s and 1s).
- Transmission Medium:
- The visible light beam acts as the carrier of the data.
- Receiver:
- A photodiode or light sensor detects the changes in light intensity and decodes the transmitted information.
🔹 Applications:
- Li-Fi (Light Fidelity):
- High-speed wireless communication using LED lights.
- Offers faster data rates than Wi-Fi in some environments.
- Underwater Communication:
- Visible light can transmit data in water where radio waves are ineffective.
- Secure Indoor Communication:
- Used in areas like hospitals or airplanes where radio frequency use is restricted.
- Smart Lighting Systems:
- Lights that provide both illumination and data transmission.
🔹 Advantages:
- High bandwidth and speed
- Reduced electromagnetic interference
- Secure — line-of-sight transmission limits data leakage
🔹 Limitations:
- Requires direct line of sight
- Blocked by obstacles (walls, opaque objects)
- Doesn’t work well in bright sunlight