[1] Marder S R, Torruellas W E, Blanchard-Desce M, Ricci V,
Stegeman G I, Gilmour S, Bredas J L, Li J, Bublitz G U and Boxer S G
1997 Science 276 1233

[2] Zhang Q F, Liu W M, Xue Z Q, Wu J L, Wang S F, Wang D L
and Gong Q H 2003 Appl. Phys. Lett. 82 958

[3] Yang G, Wang W, Zhou Y, Lu H, Yang G and Chen Z 2002
Appl. Phys. Lett. 81 3969

[4] Wang W T, Chen Z H, Yang G, Guan D Y, Yang G Z, Zhou Y L
and Lu H B 2003 Appl. Phys. Lett. 83 1983

[5] Wang Q Q, Wang S F, Huang W T and Gong Q H 2005 J.
Phys. D: Appl. Phys. 38 389

[6] Zhou Z K, Li M, Su X R, Zhai Y Y, Song H, Han J B and Hao
Z H 2008 Phys. Status Solidi A 205 345

[7] Sasaki K and Nagamura T 1998 J. Appl. Phys. 83
2894

[8] Wang Q Q, Han J B, Gong H M, Chen D J, Zhao X J, Feng J Y
and Ren J J 2006 Adv. Funct. Mater. 16 2405

[9] Zhou P, You G J, Li Y G, Han T, Li J, Wang S Y, Chen L Y,
Liu Y and Qian S X 2003 Appl. Phys. Lett. 83 3876

[10] Heitmann W 1971 Appl. Opt. 10 2658

[11] Unnikrishnan K P, Nampoori V P N, Ramakrishnan V, Umadevi
M and Vallabhan C P G 2003 J. Phys. D: Appl. Phys. 36
1242

[12] Deng X, Zhang X, Wang Y, Song Y, Liu S and Li C 1999
Opt. Commun. 168 207

[13] Chen D J, Ding S, Han J B, Zhou H J, Xiao S, Xiong G G
and Wang Q Q 2005 Chin. Phys. Lett. 22 2286

[14] Ge P, Tang S H, Ji W, Shi S, Hou H W, Long D L, Xin X Q,
Lu S F and Wu Q J 1997 J. Phys. Chem. B 101, 27

[15] Zhang C, Song Y, K\"{uhn F E, Wang Y, Fun H, Xin X and
Herrmann W A 2002 New J. Chem. 26 58

[16] Zhang W, Song Y L, Wang Y. X, Chang Q, Zhang C and Xin X
Q 2008 Chin. Phys. Lett. 25 532

[17] Song Y, Wang Y, Zhang C, Fang G, Qu S and Xin X 2001
Opt. Commun. 192 273

[18] Sheik-Bahae M, Said A A, Wei T, Hagan D J and Van
Stryland E W 1990 IEEE J. Quantum Electron. 26 760

[19] Sheik-Bahae M, Said A A, and Van Stryland E W 1989
Opt. Lett. 14 955

[20] Han J B, Chen D J, Ding S, Zhou H J, Han Y B, Xiong G G
and Wang Q Q 2006 J. Appl. Phys. 99 023526

[21] Han J B, Ding S, Chen D J, Hao Z H and Wang Q Q 2006
J. Non-Cryst. Solids 352 386

[22] Liao H B, Wen W J, Wong G K L and Yang G Z 2003 Opt.
Lett. 28 1790

[23] Zhou P, You G J, Li J, Wang S Y, Qian S X and Chen L Y
2005 Opt. Express 13 1508

[24] You G J, Zhou P, Dong, Z W, Zhang C F, Chen L Y and Qian
S X 2007 Physica B 393 188

[25] Samoc M, Samoc A, Luther-Davies B, Bao Z, Yu L, Hsieh B
and Scherf U 1998 J. Opt. Soc. Am. B 15 817

[26] Ganeev R A, Baba M, Ryasnyansky A I, Suzuki M and Kuroda
H 2004 Opt. Commun. 240 437

[27] Hayes J N 1972 Appl. Opt. 2 455

[28] Hamanaka Y, Nakamura A, Hayashi N and Omi S 2003 J.
Opt. Soc. Am. B 20 1227