Research Of Electroless Nickel Plating On The Surface Of Quartz Optic Fiber Grating And The Sensing Characters

As a kind of new-type fine passive device of optic fiber, the optic fiber grating is extensively applied to non-destructive inspection and long-term health monitoring in a lot of fields, such as navigation, civil engineering, petroleum, electricity and chemical medicine, etc. However, nowadays the package and actual engineering application of optical fiber grating sensors cannot be realized without the organic macromolecule glue. And the rigidity of the macromolecule glue is smaller than the objective examined, which made the data measured unable to reflect the physical characteristic of the object very truly; and the glue will be softened or even broken up, when it was applied in higher than 250 degrees Centigrade, while lots of more harsh monitoring environments' temperature have exceeded this range. In one word, the hermeticallity, cohere intensity, durability and heat resistance can't meet the demands by using this package technology in the harsh environment. In order to improve the measurement accuracy of the optic fiber grating and make it can be applied to more high-temperature, need to protect the quartz optic fiber grating by metallized it's surface, then fixed and packaged it by metallization technology.Metallization packaging the optic fiber grating after electrolessed nickel plating on its surface, need well cohesion and solderable, and the nickel layer could be applied to weld after reaching certain thickness. This text is about how to electroless nickel plating on the surface of optic fiber grating, the layer's functions, and the sensing characteristic of the optic fiber grating after it metallization packaged. The main works are as follows:1) Considered the experiments of pretreatment and the characteristic of optic fiber grating, a new process of the pretreatment of electroless nickel plating on the surface of optical fiber was found.2) Based on the analysis of essential composition of plating solution, the chemicals of making up the electroless plating solution were chosen. Compared with different experiments of different formulas and the research of plate speed and the cohesion between the layer and the optic fiber, two groups of acidly high speed electroless nickel plating solution (set as A and B) were invented.3) The layer's shape was observed by the scanning electronic microscope, and the content of nickel and phosphorus were measured by the EDAX of the SEM, and the application of used in room temperature to 700 degrees Centigrade was examined, too. The layers made by the two kinds plating solution, those appearance and functions in the room temperature are very good. In the two kinds of layers, the function of the layer made by the A plating solution is better than that of the layer made by the B plating solution in the range of room temperature to 300 degrees Centigrade, which is contrary in the range of 300 degrees Centigrade to 700 degree Centigrade.4) When the optic fiber grating was metalized by the electroless nickel plating process on the optical fiber and monitored by the OSA, found that this process doesn't affect the grating's sense characteristic.5) Successfully packaged the metalized optic fiber grating sensor. Compared with the sensing characteristics of metallization package and macromolecule glue package, the sensing linear and repeatlity of the former are obviously better than the latter.Generally speaking by metalized on the surface of the optic fiber grating and fully metallization packaged it, not only improved the sense characters, but also greatly expended its applied range.