光纤PCVD工艺等离子体有源区场的分析

The Analysis of Electric Field in Plasma Active Zone in Optical Fiber PCVD Process

对光纤ＰＣＶＤ（等离子体化学气相沉积）制造工艺的微波等离子体有源区的性质进行了分析，指出微波电场是使反应物电离的决定因素之一，而反应物电离后生成的带电微粒，又影响微波的传输，使微波传输线由原来的驻波状态变为行波状态。进而，对有源区的电子密度分布进行了分析，导出了光纤ＰＣＶＤ工艺有源区微波场满足的亥姆霍兹方程并进行了数值求解。结果表明：有源区微波场的分布是不均匀的，在等离子体柱中心最大。

In this paper, the characteristics of microwave plasma active zone in the optical fiber PCVD process are described where we point out that microwave electic field is one of the predominant factors to gas discharge, and the charged particles affect microwave propagation too such that make the microwave vary from standing wave to traveling wave. The electron density distribution in active zone, is analyzed and the helmholtz equation met by electric field is deduced. The numerical results indicate that microwave electric field amplitude in active zone is inhomogeneous, the greatest being at the center of the plasma cylinder, and is related to the electron density distribution closely.