[1] Li F, Yu X, Gu H, et al. Applied Optics, 2011, 50(36): 6697.

[2] Seidel A, Wagner S, Ebert V. Applied Physics B-Lasers and Optics, 2012, 109(3): 497.

[3] Li J S, Parchatka U, Konigstedt R, et al. Optics Express, 2012, 20(7): 7590.

[4] Dummer M M, Sysak M N, Tauke-Pedretti A, et al. Journal of Lightwave Technology, 2008, 26(8): 938.

[5] Gao Y, Cao L, You Z, et al. Optics Express, 2013, 21(4): 5063.

[6] Kolachevsky N, Alnis J, Parthey C, et al. Optics Letters, 2011, 36(21): 4299.

[7] Gatto A, Boletti A, Boffi P, et al. Optics Express, 2009, 17(24): 21748.

[8] Nan G A O, Zhenhui D U, Rubin Q I, et al. Journal of Optoelectronics·Laser, 2011, 22(6): 893.

[10] Ke J H, Zhu N H, Xie L, et al. Optics Communications, 2011, 284(5): 1312.

[11] Liu Y, Ye N, Zhou D B, et al. Chinese Physics Letters, 2011, 28(2).

[12] Weldon V, Pineda-Vadillo P, Lynch M, et al. Applied Physics B-Lasers and Optics, 2012, 109(3): 433.

[13] Dong L, Zhang R, Wang D, et al. Journal of Lightwave Technology, 2009, 27(15): 3181.