Certified Fiber Optics Practice Exam

What device is typically used by fiber optic receivers to detect light?

1. Transmitter

2. Photodiode

3. Amplifier

4. Converter

The correct answer is: Photodiode

Fiber optic receivers rely on photodiodes to detect light signals transmitted through fiber optic cables. Photodiodes are semiconductor devices that convert light into electrical current. When light, typically in the form of a laser or LED light, enters the photodiode, it generates electron-hole pairs, which leads to the flow of current. This current can then be processed to retrieve the original data that was transmitted. In the context of fiber optics, the performance of the photodiode is crucial as it must respond quickly to changes in light intensity and operate efficiently over the wavelength range used in optical communication. Other devices like transmitters, amplifiers, and converters have distinct roles in a fiber optic system. Transmitters generate the light signals, amplifiers increase the signal strength during transmission, and converters can change signals from one format to another, but none are responsible for the direct detection of light signals as photodiodes are.