Absorption-Type Optical Fiber Gas Sensor Chamber Structure And The Optical Loss Analysis

With the scientific and technological progress, especially infrared light-emitting device and infrared detection technology was developed by leaps and bounds in recent years, efficient, low-voltage, small size of the device continuously,which has created conditions for the development of infrared sensing technology. Infrared gas sensor has a solid foundation in physics, and its application in gas detection is very extensive. Absorption optical fiber gas sensor is a sensor which is based on the gas molecules on the infrared light absorption characteristics have a stronger foundation developed. Absorption chamber is one of the main devices of absorbing optical fiber gas sensor.The thesis research work carried out as follows:First of all, introduces a variety of optical gas detection technology, reviewed the fiber-optic gas sensor research and development trends of domestic and international, analyses the role in the influencing factors, key technologies and major component of the optical fiber gas sensors.Secondly, expounds the theory which light absorption and scattering at medium, the interface transmittance and reflectance of optical in the isotropic media interface, light at the metal surface reflectivity, GRIN lens refractive index distribution and the basic principles, such as insertion loss.Finally, an analysis of three typical air chamber (namely, absorption-type air chamber, reflective air chamber)structure and working process, And in accordance with optical absorption and scattering theory, the lens surface of the transmission and reflection at the metal surface, as well as optical reflectivity, such as the theory of absorptive and reflective air chamber air chamber for the optical loss of the theoretical calculations and comparisons; then, through the test method to detect the GRIN lens with the absorption-type air chamber of the optical loss.