Fiber optic sensors use which medium to send and receive light?

Fiber optic sensors use which medium to send and receive light?

• A. Sound
• B. Temperature
• C. Radio
• D. Light

Answer: (D)

The signal in fiber optic sensors is carried by light. The optical fiber, usually glass or plastic, acts as a waveguide that confines light in its core by total internal reflection, allowing the light to travel long distances with little loss. The sensor detects changes in the light’s properties—such as intensity, phase, wavelength, or polarization—caused by the physical quantity being measured (like temperature or strain) and converts that into a readable signal. Sound would be a mechanical wave, temperature is the thing being measured rather than the carrier, and radio waves are a different form of electromagnetic communication; none of these serve as the light-based carrier in fiber optics.

The signal in fiber optic sensors is carried by light. The optical fiber, usually glass or plastic, acts as a waveguide that confines light in its core by total internal reflection, allowing the light to travel long distances with little loss. The sensor detects changes in the light’s properties—such as intensity, phase, wavelength, or polarization—caused by the physical quantity being measured (like temperature or strain) and converts that into a readable signal. Sound would be a mechanical wave, temperature is the thing being measured rather than the carrier, and radio waves are a different form of electromagnetic communication; none of these serve as the light-based carrier in fiber optics.