[1] K. J. Vahala, Nature 424, 839 (2003).

[2] G. Gu, L. Chen, H. Fu, K. Che, Z. Cai, and H. Xu, Chin. Opt. Lett. 11, 101401 (2013).

[3] C. Dong, C. Zou, J. Cui, Y. Yang, Z. Han, and G. Guo, Chin. Opt. Lett. 7, 299 (2009).

[4] M. Bayer, T. Gutbrod, J. P. Reithmaier, A. Forchel, T. L. Reinecke, P. A. Knipp, A. A. Dremin, and V. D. Kulakovskii, Phys. Rev. Lett. 81, 2582 (1998).

[5] M. Benyoucef, J. B. Shim, J.Wiersig, and O. G. Schmidt, Opt. Lett. 36, 1317 (2011).

[6] S. V. Boriskina, J. Opt. Soc. Am. B 23, 1565 (2006).

[7] K. Che, M. Lei, G. Gu, Z. Cai, and Y. Huang, Appl. Opt. 52, 8190 (2013).

[8] L. I. Deych, C. Schmidt, A. Chipouline, T. Pertsch, and A. T¨unnermann, Phys. Rev. A. 77, 051801 (2008).

[9] J. V. Hryniewicz, P. P. Absil, B. E. Little, R. A. Wilson, and P-T. Ho, IEEE Photon. Technol. Lett. 12, 320 (2000).

[10] Y. Huang, J. Lin, Q. Yao, X. Lv, Y. Yang, J. Xiao, and Y. Du, Chin. Opt. Lett. 10, 091404 (2012).

[11] J. Li, J. Wang, and Y. Huang, Opt. Lett. 32, 1563 (2007).

[12] T. W. Lu and P. T. Lee, Opt. Express 17, 1518 (2009).

[13] A. A. Savchenkov, V. S. Ilchenko, A. B. Matsko, and L. Maleki, IEEE Photon. Technol. Lett. 17, 136 (2005).

[14] L. Shang, L. Liu, and L. Xu, Opt. Lett. 33, 1150 (2008).

[15] E. I. Smotrova, A. I. Nosich, T. M. Benson, and P. Sewell, Opt. Lett. 31, 921 (2006).

[16] F. N. Xia, M. Rooks, L. Sekaric, and Y. Vlasov, Opt. Express 15, 11934 (2007).

[17] Y. Sato, Y. Tanaka, J. Upham, Y. Takahashi, T. Asano, and S. Noda, Nat. Photon. 6, 56 (2011).

[18] A. Tavlove and S. C. Hagness, Computational Electro-dynamics: the Finite-difference Time-domain Method (Artech House, Norwood, 1995).

[19] W. Guo, W. Li, and Y. Huang, IEEE Microw. Wireless Compon. Lett. 11, 223 (2001).

[20] Y. Yang, S. Wang, and Y. Huang, Opt. Express 17, 23010 (2009).

[21] C. C. Katsidis and D. I. Siapkas, Appl. Opt. 41, 3978 (2002).

[22] X. Lv, Y. Huang, Y. Yang, H. Long, L. Zou, Q. Yao, X. Jin, J. Xiao, and Y. Du, Opt. Express 21, 16069 (2013).