Which data encoding technology is used in fiber-optic cables?
pulses of light
modulation of electrical voltage
modulation of specific frequencies of electromagnetic waves
electrical pulses
The correct answer and explanation is :
Correct Answer:
Pulses of light
Explanation:
Fiber-optic cables use pulses of light to transmit data over long distances with high speed and minimal signal loss. Unlike traditional copper cables, which use electrical signals, fiber-optic cables rely on total internal reflection to guide light through the cable’s core. This allows data to travel at nearly the speed of light.
How It Works:
- Encoding Data into Light Pulses:
- A laser or LED light source generates pulses of light representing binary data (0s and 1s).
- A pulse of light corresponds to a binary “1,” while the absence of a pulse represents a binary “0.”
- Transmission Through the Fiber:
- The fiber core is made of glass or plastic with a high refractive index, surrounded by cladding with a lower refractive index.
- Due to total internal reflection, light is continuously reflected within the core, allowing it to travel long distances without escaping.
- Decoding at the Receiver End:
- A photodetector at the receiving end converts the light pulses back into electrical signals.
- These signals are then processed by network devices such as routers or computers.
Why Fiber-Optic is Superior to Electrical Transmission?
- Higher Speed: Can transmit data at speeds up to terabits per second.
- Lower Signal Loss: Less attenuation over long distances compared to electrical cables.
- Immunity to Electromagnetic Interference: Unlike electrical signals, light is not affected by external electromagnetic interference.
- Greater Bandwidth: Can carry more data than copper cables.
Thus, pulses of light are the fundamental data encoding technology used in fiber-optic communication systems.