[5] Kurtz C. N., Streifer W.. Guided waves in inhomogeneous focusing media. Part Ⅰ and Ⅱ[J]. IEEE Trance. Microwave Theory and Technol., 1969, MTT-17(1): 11~15, 250~253
[6] Hashimoto M., Nemoto S., Makimoto T.. Analysis of guided waves along the cladded optical fiber: Parabolic-index core and homogeneous cladding[J]. IEEE Trance. Microwave Theory and Technol., 1977, MTT-25(1): 11~17
[7] Yamada R, Inabe Y. Guided waves in an optical square-law medium[J]. J. Opt. Soc. Am., 1974, 64(7): 964~968
[9] Gloge D. Weakly guiding fibers[J]. Appl. Opt., 1971, 10(10): 2252~2258