Font Size: a A A

Research For Composite Interference Optical Sensor Based On Multimode Fiber Structure

Posted on:2016-11-20Degree:MasterType:Thesis
Country:ChinaCandidate:J SuFull Text:PDF
GTID:2308330461989321Subject:Information and Communication Engineering
Abstract/Summary:PDF Full Text Request
In the new era of science and technology rapid developed, the three pillars of modern information technology(Senor technology, communication technology and computer technology), has been deep into all fields, and plays important roles. In the field of the sensor technology, optical fiber sensing technology is the most rapid development, and the direction of the new generation of sensors. Optical fiber sensors have been extensively investigated due to their advantages of high sensitivity, compact size, and immunity to electromagnetic interference, etc. Optical fiber sensor has been recognized as one of the most promising high-tech industry, it takes the characteristics of high technological content, good economic returns, penetration ability, broad market prospects attracted worldwide attention.Compared with the conventional sensors, the fiber-interference-based sensor has broad response range, much higher sensitivity and resolution, and is also stable under special working environment, which has been applied in many sensing areas, such as temperature,strain, liquid level, refractive index, humidity and hydrophone.In the thesis, two types of optical fiber sensors have been proposed based on modal interference, and since different interference peaks have different spectral responses to temperature, liquid level and refractive index(RI), simultaneous measurement can be realized by the sensor structure. In addition, the characteristics of their liquid level sensing have also been discussed. The main content includes:(1)Depict generally on the basic principles and classification of the optical fiber sensor,and introduce the optical fiber sensing technology based on modal interference. The research progress of fiber model interferometric sensors has also been briefly described.(2)A novel sensor of multimode-multimode-multimode(MMM) fiber structure based on modal interference has been proposed. The output signal is a series of interference signal superposition, which includes core-core mode interference and core-cladding mode interference. Since different interference peaks have different spectral responses to temperature, refractive index and liquid level, simultaneous measurement can be realized by the sensor structure.(3)A novel sensor of multimode-single mode-multimode(MSM) fiber structure based on modal interference has been designed. It can be regarded as a cascade of the traditional single mode-multimode-single mode(SMS) structure and the MSM structure. The output signal is a series of interference signal superposition, which include core-core mode interference produced by SMS structure and core-cladding mode interference produced by MSM structure.Since interference peaks of the SMS structure and the MSM structure have different spectral responses to temperature and RI, simultaneous measurement can be realized by the sensor structure.
Keywords/Search Tags:Interference-based optical fiber sensors, Modal interference, Composite interference, Simultaneous measurement
PDF Full Text Request
Related items