[1] [1] L. Chen, IEEE Photon. Technol. Lett. 16, 410 (2004).

[2] [2] K. Mizuuchi, K. Yamamoto, M. Kato, and H. Sato, IEEE J. Quantum Electron. 30, 1596 (1994).

[3] [3] J. Xie, Y. Chen, W. Lu, and X. Chen, Chin. Opt. Lett. 9, 041902 (2011).

[4] [4] M. H. Chou, I. Brener, M. M. Fejer, E. E. Chaban, and S. B. Christman, IEEE Photon. Technol. Lett. 11, 653 (1999).

[5] [5] J. Zhang, Y. Chen, F. Lu, and X. Chen, Opt. Express 16, 6957 (2008).

[6] [6] G. Schreiber, H. Suche, Y. L. Lee, W. Grundkotter, V. Quiring, R. Ricken, and W. Sohler, Appl. Phys. B 73, 501 (2001).

[7] [7] Y. W. Lee, F. C. Fan, Y. C. Huang, B. Y. Gu, B. Z. Dong, and M. H. Chou, Opt. Lett. 27, 2191 (2002).

[8] [8] M. M. Fejer, G. A. Magel, D. H. Jundt, and R. L. Byer, IEEE J. Quantum Electron. 28, 2631 (1992).

[9] [9] D. Hofmann, G. Schreiber, C. Haase, H. Herrmann, W. Grundkotter, R. Ricken, and W. Sohler, Opt. Lett. 24, 896 (1999).

[10] [10] S. Kirkpatrick, C. D. Gelatt, and M. P. Vecchi, Science 220, 671 (1983).

[11] [11] J. Wang, J. Sun, X. Zhang, and D. Huang, J. Lightwave Technol. 26, 3137 (2008).