Plasma Chemical Vapor Deposition ( PCVD ) is an important application in making optical fiber core rod. The resonator is the key part for PCVD application. But the existing resonator have several serious disadvantages: its working is not stable; the size of deposited substrate tube is small(Ø31mm); the deposition rate is low(2.5g/min) and the deposition effect is unsymmetrical; the fabrication of the resonator is very difficult and expensive. Therefore, a new type of resonator, a cylinder resonator, is designed to overcome the above disadvantages. The cylinder resonator supports bigger substrate tube (Max Ø60mm) and higher deposition rate(3.2g/min) than existing ones, while its working is also more stable. Since the structure is more simple, the fabrication is easier and cheaper. The corresponding microwave theoretical method of the new resonator designing is also introduced with the necessary computer simulation, as well as test running. And TE111 mode microwave is the Fundamental Mode of the cylinder resonator. The cylinder resonator has been applied in normal production for 4 years, which is better for bigger size core rod making, improving the optical fiber quality and saving cost. It is estimated, after modification with the cylinder resonator and 10kW microwave generator, a PCVD lathe can yield 30% more rods than before.

Plasma Chemical Vapor Deposition process is one of the main process to make optical fiber core-rod. In this process, gas flow, pressure, furnace temperature, reflective microwave power , resonator moving speed and deposition rate are dependant aspects. An artificial neural network model is set up to describe the relationship of variables in the process, and also verified by the experiment and production. Based on the ANN-model, the process recipe setting is illustrated in the paper.

The nonlinear FEM analysis is performed to the problem of large strain nonlinear application for flexible mattress. The element with cloth type option is used to establish the FEM model for the analysis of flexible mattress. The simulation can produce correct profile of deformation, accurate distribution of stress and strain, meanwhile taking account of geometric nonlinear from large strain. The results of the paper are compared with those from the theory and in-situ test. Some valuable conclusions are made from the results analysis.

A lumped mass method is presented to analyze the tension force subjected by flexible mattress and its configuration. The method can take account of the elastic extension, non-uniform mass distribution of the mattress and the acting force due to flowing water. Through comparison between calculation results of this paper and catenary theory, it verifies the lumped mass method is more applicable for analysis of flexible mattress in real fluvial environment than commonly used catenary theory.

The Core Rod made by Plasma Chemical Vapor Deposition process is measured by PK2600 for Refractive Index Profile. The measurement data is very important to justify the core rod quality. A method based on DWT is presented in this paper to discover some information which is difficult to emerge according to conventional way. The analysis result can be used to optimize the core-rod making process.