Fiber-Optic Sensors | Eight Reasons Fiber Amplifiers Outperform Other Sensors

Optical communication is an old technique. Historically, a hand might modulate light and an eye detect it, but air propagation has limitations that do not meet modern electronics requirements. In 1966 Kao and Hockham proposed using low-loss optical fiber to guide light, enabling stable long-distance optical transmission. The development of fiber-optic sensors began around 1977 and the technology has progressed rapidly since.

Fiber-optic sensors and fiber amplifiers have developed quickly because they offer many advantages unmatched by other sensors. These advantages include:

① Electrical insulation

Since fiber is a dielectric and sensing elements can be dielectric, fiber-optic sensors provide excellent electrical insulation. Fiber surfaces can withstand high voltages (e.g., 80 kV/20 cm), making them suitable for high-voltage systems and large motors.

② Immunity to electromagnetic interference

This unique feature makes fiber sensors ideal for harsh environments with high currents, strong magnetic fields, noise and radiation.

③ Non-intrusive

Sensing heads can be electrically insulated and very small (core diameters slightly larger than fiber), so they are non-intrusive to electromagnetic and flow fields and do not disturb the measured field. This is valuable for monitoring weak electromagnetic fields and small-pipe flow.

④ High sensitivity

High sensitivity is an advantage of optical measurement. Fiber-based sensing achieves excellent sensitivity and is an important tool for precise measurement and control.

⑤ Remote monitoring is easy

Because fiber transmission loss is low, fiber sensors combined with telemetry enable easy remote monitoring of measurement sites—critical for industrial control and for monitoring radiation, flammable/explosive gases and air pollution.

⑥ Geometric adaptability

Fiber sensors can adopt many shapes and form arbitrary sensing geometries. Fiber also offers water resistance, corrosion resistance and high data transmission density.

Moreover, fiber sensors can detect acceleration, velocity, displacement, angular acceleration, angular velocity, angular position, pressure, bending, strain, torque, temperature, voltage, current, liquid level, flow, concentration and pH. Compared with electric-based traditional sensors, fiber-optic sensors differ fundamentally in measurement principles and offer unique advantages.

Traditional electric sensors convert measured states into electrical signals using power supplies, sensing elements, signal reception and processing and metal wiring. Fiber-optic sensors convert measured states into optical signals; a light emitter guides light to a sensing element where the measurement modulates a light characteristic, and the modulated light is coupled to a photodetector and converted to an electrical signal for processing.

Atonm fiber-optic sensors include high-end features such as digital display tuning, operation in confined spaces, high-temperature measurements, near-field small-object detection, zone discrimination, mixed-material differentiation, counting, zero-drift suppression, automatic optical gain, anti-light-interference modes and percentage-based detection.

Atonm fiber sensors are commonly used in food packaging, metal equipment, pharmaceuticals, 3C and LED electronics for material-mixing detection, correct-side detection, presence detection and tablet counting.