A fiber optic sensor is a sensor that converts the state of a measured object into a measurable optical signal. The working principle of a fiber optic sensor is as follows: a light beam incident from a light source is sent through an optical fiber to a modulator. Within the modulator, the light interacts with the external parameters to be measured, causing changes in the optical properties of the light, such as intensity, wavelength, frequency, phase, and polarization state, becoming a modulated optical signal. This modulated signal is then sent through an optical fiber to a photoelectric device, and finally demodulated to obtain the measured parameters. Throughout the process, the light beam is guided through the optical fiber, passes through the modulator, and then exits. The optical fiber's primary function is to transmit the light beam, and secondly, it acts as an optical modulator. Next, we will explain in detail the characteristics and main advantages of fiber optic sensors.
1. What are the characteristics of fiber optic sensors?
1. High sensitivity;
2. Its geometry offers versatility, allowing for the fabrication of fiber optic sensors of any shape;
3. It can manufacture devices that sense various physical information (sound, magnetism, temperature, rotation, etc.);
4. It can be used in high-voltage, electrical noise, high-temperature, corrosive, or other harsh environments;
5. Moreover, it has inherent compatibility with fiber optic telemetry technology.
The advantages of fiber optic sensors compared to traditional sensors are that they use light as the carrier of sensitive information and optical fiber as the medium for transmitting sensitive information, possessing the characteristics of fiber optic and optical measurement, and offering a series of unique advantages. These include good electrical insulation, strong resistance to electromagnetic interference, non-invasiveness, high sensitivity, ease of long-distance monitoring of the measured signal, corrosion resistance, explosion-proof properties, and flexible optical path for easy connection to computers.
Sensors are developing towards greater sensitivity, accuracy, adaptability, compactness, and intelligence. They can act as the eyes and ears of humans in places inaccessible to humans (such as high-temperature areas or areas harmful to humans, such as nuclear radiation areas), and can even transcend human physiological limits to receive external information that cannot be perceived by human senses.
2. Main advantages of fiber optic sensors
Compared to traditional electrical sensors, fiber optic sensors have the following advantages:
(1) The sensor probe has a simple structure, small size and light weight, and can measure the strain and structural damage of the structure.
(2) It has natural compatibility with optical fibers, no electromagnetic interference, easy connection with optical fibers, low loss, good spectral characteristics, and high reliability.
(3) It is non-conductive, has little impact on the measured medium, and is also corrosion-resistant and electromagnetic interference-resistant, making it suitable for working in harsh environments.
(4) Lightweight and flexible, multiple gratings can be written into a single optical fiber to form a sensor array.
(5) The multiplexing of fiber optic sensors is a unique technology of fiber optic sensors, which enables the measurement of the distributed field along the fiber optic laying path.
