[1] Durhuus T,Mikkelesen B,Joergensen C et al. J Lightwave Technology,199 6;14(6):942~954
[2] Ellis A D,Kelly A E,Nesset D et al. Electron Lett,1998;34(20):1958~1959
[3] Qiao Y J, Yu J J,Chi N et al.Acta Photonica Sinica,1999;28(6):517~521
[4] Zhang X L, Sun J Q, Huang D X at al. Journal of Huazhong University of Science and Technology.1999;27(10):18~20