光纤传感技术（Optical fiber sensing technology）.docVIP

光纤传感技术（Optical fiber sensing technology） Optical fiber sensors are mainly sensing and light transmission type of two categories, two The sensor can be divided into light intensity modulation and phase modulation in the sensing principle Different forms of modulation, polarization modulation, and wavelength modulation form different Sensors 2.1 fiber Fabry- Perot sensors Optical fiber Fabry- P Erot (F- P) sensor is made of optical fiber F - the P interferometer, the F- P cavity, is the core of the sensor. Fiber F - P sensing The utility model is mainly composed of two end faces which are parallel and coated, and are tightly sealed in a cylindrical knot Composition of optical fiber in the structure. Incident light is reflected and occurs at the two ends respectively They are incident light wavelength and intracavity refraction The rate of. When the external effect causes the cavity length L to change, it can pass through the cavity The change of the reflected light intensity caused by phase changes; the perception of external effects Small。 2., 1. fiber F- P sensors 2.2 fiber Sagnac sensors Fiber Sagnac sensor based on Sagnac interference principle, laser The beam is divided into two beams and enters the optical fiber ring from both ends, and enters the probe from one end Sensors. Non reciprocal optical path difference of two opposite beam in optical fiber ring The angular velocity perpendicular to the plane of the fiber ring and the inertial space:. Correct by phase difference Rotate relative to inertial space optical fiber ring. 2.3 fiber grating sensor Grating Bragg sensor 2.4 fiber micro bend sensor 2.5 light intensity coupling displacement sensor 2.6 fiber optic fluorescence sensor The temperature characteristics of fluorescent materials are the basis of temperature measurement and trace rare earth phosphorus Compound is mixed with fiber, which can emit fluorescence probe. . The intensity or life of light varies with temperature, and changes can be detected To th