Study Of Optical Spectrum Characteristics Of Fiber Grating Coated With Swcnt

Coating Fiber Grating (CFG) uses fiber grating as its basic functional component. And membrane structure is made with a few kinds of materials which have optical, electrical and mechanical property. Using coating technology, membrane and fiber grating are combined and the fiber grating is given new optical, technical and mechanical properties. With its excellent optical property and agile design method, CFG possesses a promising future in the fields of fiber optical communication and fiber optical sensors.Single-walled carbon nanotubes(SWCNT) is a coaxial tube constituted by hexagon arrangement carbon atoms. It has the properties of good flexibility, high intensity, light weight and good conductivity. Recently, there have been researches in communication field on a new fiber apparatus combining SWCNT and fiber grating, which can be used as the attenuator of saturation absorber using its unique spectral characters. But there is few researches on this new fiber apparatus in sensor field and this study still has many questions to be solved.This thesis mainly studies coating fiber gating theoretically and experimentally. A kind of SWCNT coating fiber gating is obtained and its spectral character is studied. This thesis mainly includes the following chapters:In chapter 1 the basic knowledge of carbon nanotubes, fiber grating, coating fiber gratings and their development tendency in domestic and abroad are introduced.In chapter 2 the basal theory of coating fiber gratings are introduced. Starting with sensing theory of fiber gratings, the properties of Fiber Bragg grating and long-period grating coated with carbon nanotube is studied.In chapter 3 the properties of carbon nanotube is studied including electrical and optical characteristic and the influence of different polarized lights on CNT's absorption characteristic. It also demonstrates coating method of CNT and preparation method of CNT's coating liquid.In chapter 4 the spectral properties of single-walled carbon nanotube coating fiber grating is studied. Some optical effects such as light amplitude limiting of the SWCNT coating fiber grating was observed in the experiment.