Multi-component phosphate laser surface treatment of glass

Title: Multi-component phosphate laser surface treatment of glass
　　Author: Yang Gang
　　Degree-granting units: South China University of Technology
　　Keywords: phosphate glass optical fiber;; surface;; chemical dissolution;; high temperature treatment
　　Summary:
　　Narrow linewidth single frequency (or single-longitudinal-mode) fiber laser as excellent beam quality, narrow linewidth and low thermal effects, etc., and in the laser radar, laser ranging, optical sensing and ultra long-range detection and other areas a strong demand. Currently the use of multi-component rare earth-doped phosphate fiber has been achieved using a Neodymium magnets short cavity single frequency laser output. However, even with high purity raw materials and fine-melting, multi-component active phosphate fiber transmission loss is also much higher than the intrinsic loss of phosphate glass. Studies have shown that this loss mainly from the fiber core and cladding interface defects between. When the tube Bangfa optical fiber preform preparation, it is inevitable in the fiber surface, sub surface, leaving scratches, holes and other defects, and surface adsorption of impurities in the glass preform. These defects and residual impurities in the phosphate glass fiber drawn core / cladding interface, caused by optical scattering and absorption of light, an increase of fiber loss. In response to these issues, the issue focused on the chemical treatment of the fiber preform to improve phosphate fiber core / cladding interface quality, low loss for the drawing of multi-component rare earth-doped phosphate fiber, developed single-frequency narrow-linewidth fiber laser lay the material foundation.
　　Experiments selected optical spectroscopic properties of a good, stable physical and chemical properties of multicomponent phosphate glass 60.9P2O5-15BaO-10Al2O3-1.5Er2O3-12.6 (K2O-Nb2O5-Sb2O3 - Yb2O3) for the study to explore the rare earth-doped phosphate salt laser glass in acidic solution of the chemical dissolution mechanism. Analysis of the acid solution acid concentration, solution temperature, dissolution time and the role of multi-component ultrasonic phosphate chemical etching of glass. Based on thermodynamic and kinetic theory, discussed the acid etching solution on the response to the direction of the phosphate glass, limit, restrict speed of response of various factors, the mass loss curve of the glass, etching in the dissolution rate curve and the ion concentration curve the fitting, the establishment of a dissolution kinetics model. Accordingly, a variety of erosion control reaction parameters were optimized. Experiments show that the phosphate glass etching acid solution to eliminate the glass surface scratches and other defects.
　　It was found that, with the reaction time, phosphate glass surface of hydrochloric acid insoluble crystalline granular coating. This cover has seriously hindered the further hydrochloric acid dissolved in the glass, and these particles reduces the crystallization of glass transmittance. Through glass fiber drawing temperature heat treatment, because http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php small particles have a lower melting point, crystallization of the glass surface of the micron-scale particles can be re-glass, and improve the light transmittance of glass.
　　Studies have shown that the use of chemical etching and a combination of high temperature heat treatment method can effectively improve the phosphate glass optical fiber preform surface smoothness, removes impurities in the glass surface, thus improving the optical fiber preform drawn phosphate core / cladding interface matching to reduce fiber loss.
　　Degree Year: 2010