Study On All Fiber Interferometer Temperature Sensors

Optical fiber sensing technology have attracted considerable research interests inrecent years because of their long distance transmission, ease of networking, highsensitivity and high reliability. There’s no substitute for optical fiber sensingtechnology to harsh environment. As one type of optical fiber sensor, the optical fiberinterferometers can be applied to many sensing applications with its high resolution,high accuracy and high dynamic range. Compared to optical fiber grating sensors, thesize of the optical fiber interferometers is smaller, which can achieve accuratemeasurement, and suitable for narrow installation location.In this dissertation, three all-fiber interferometers are designed and fabricatedbased on femtosecond laser processing technology and arc splicing technology.Experimental results show that the sensors all have high stability and good sensitivity.The main contents are listed as follows:（1） The materials micromachining methods and procedures with fs lasermicromachining have been investigated systematically. Thus, the miniatureinterferometric optical fiber temperature sensors can fabricated with optimalprocessing parameters.（2） The parameters in the process of splicing are discussed in detail.Different arc power、duration time、prefusion time and gap distance was studied toconfirm the splicing parameters. Experiments show that the round-trip insertion lossof the sensor is0.56dB.（3） The optical fiber temperature sensors based on interferometer, such asMichelson interferometer and Fabry-Perot interferometer, are analyzed and discussedunder different conditions, and the novel sensors have high potential in temperaturesensing. Three kind of all optical fiber sensors which are fabricated by femtosecondlaser micromachining and arc splicing technique, are proposed and demonstrated.When used in temperature sensing, such interferometers operate in a reflection modeof detection, and exhibit a compact sensor head, good mechanical reliability, wideoperation range, and high sensitivity.