How Do Fiber Optic Sensors Work?

Fiber optic sensors use the physical properties of optical fibers to detect external parameters. They consist of a light source, fiber, modulator, demodulator, and photodetector. The light interacts with measured parameters (temperature, pressure, displacement) to modulate optical properties such as intensity, wavelength, phase, or polarization, which are then converted to electrical signals for measurement.

Fiber optic sensors can be intensity-based, interferometric, wavelength-based, or polarization-based. Intensity sensors are simple but sensitive to environment. Interferometric sensors are highly sensitive but require precise alignment and stable temperature. Wavelength sensors enable multiplexing and remote sensing but need complex analyzers. Polarization sensors resist electromagnetic interference but require special fibers and analyzers.

Applications include temperature, pressure, displacement, strain, flow, and liquid level monitoring. Fiber sensors excel in harsh environments, high temperature, and areas with strong electromagnetic fields, and support distributed and remote sensing.