2TONG W, WANG H, LUO J, et al. Fabrication of Long-length & Low-loss PMF and Measurement of its properties[R]. APOC,2005.
3MATSUMUR H.Optical fiber and method of producing the same[P]. US Patend,1984, No4426129.
4SUZANNE Ro NAGEL. J. B, MACCHESNEY. AND KENNETH L. WALKER An Overview of the Modified Chemical Vapor[R]. Deposition (MCVD) Process and performance,1982.