Langmuir-Blodgett films second-harmonic generation

Leigh D A, Moody A E, Wade F A, King T A, West D and Bahra G S 1995 Second harmonic generation from Langmuir-Blodgett films of fullerene-aza-crown ethers and their potassium ion complexes Langmuir 11 2334-6... 

Amino-5-nitropyrimidine, cocrystallization, 455 Amorphous polymers, criteria for use in second harmonic generation, 250-251 Amphiphilic molecules polar Z-type Langmuir-Blodgett films, formation, 473-479 structures, transfer behavior, and contact angles, 474,476-477r Anharmonic oscillator models, nonlinear optical effect-microstructure relationship, 361... 

Yamada, S., Nakano. T., Matsuo, T. Second harmonic generation from Langmuir-Blodgett monolayers of amphiphilic ruthenium(II) complexes structural characterization with polarization measurements. Thin Solid Films 245, 196-201 (1994)... 

SECOND-HARMONIC BLUE LIGHT GENERATION IN LANGMUIR-BLODGETT FILM WAVEGUIDES BY MODE CONVERSION AND BY USE OF THE CERENKOV-TYPE CONFIGURATION... 

In this paper we report phase-matched second-harmonic generation in nonlinear optically active Langmuir-Blodgett (LB) film waveguides both by mode conversion and by use of the Cerenkov-type configuration. The experiments were done in 2-docosylamino-S-nitropyridine (DCANP) LB films (Hg.l). The synthesis, the optimum conditions for LB film transfer and the linear and nonlinear optical properties of this material have been described elsewhere [4-6]. 

L.M. Hayden, S.T. Kowel, and M.P. Srinivasan, Enhanced second harmonic generation from multilayered Langmuir/Blodgett films of dye. Opt. Commun. 61 351 (1987). 

I. Ledoux, D. Josse, P. Fremaux, J.P. Piel, G. Post, J. Zyss, T. McLean, R.A. Hann, P.F. Gordon and S. Allen, Second harmonic generation in alternate non-linear Langmuir-Blodgett films. Thin Solid Films 160 217 (1988). 

B.L. Anderson, R.C. Hall, B.G. Higgins, G. Lindsay, P. Stroeve, and S.T. Kowel, ( uadrati-cally enhanced second harmonic generation in polymer-dye Langmuir-Blodgett films a new bilayer architecture, Synth. Met. 28 D683 (1989). 

G. Decher, B. Tieke, C. Bosshard, and P. Gunter, Optical Second-harmonic Generation in Langmuir-Blodgett Films of 2-Docosylamino-5-nitropyridine, T. Chem. Soc. Chem. Commun. 933 (1988). 

G. H. Cross, I. R. Peterson, I. R. Girling, N. A. Cade, M. J. Goodwin, N. Carr, R. S. Sethi, R. Marsden, G. W. Gray, D. Lacey, A. M. McRoberts, R. M. Scrowston, and K. J. Toyne, A comparison of second harmonic generation and electro-optic studies of Langmuir-Blodgett monolayers of new hemicyanine dyes. Thin Solid Films 156 39 (1988). 

So far, no specific assumptions have been made about the orientation of the molecules. In crystals and Langmuir-Blodgett films there are preferred pointing directions of the molecules however, polymer films typically show a random orientation of the chromophores after deposition. Since there is no net orientation, the polymer appears centrosymmetric from a macroscopic point of view and, therefore, does not show any significant second-order nonlinear response. Consequently, it is necessary to break this centrosymmetry for efficient second-harmonic generation. 

Fldrsheimer, M., Kiipfer, M., Bosshard, C., Looser. H., and GUnter, P., Phase-matched optical second-harmonic generation in Langmuir-Blodgett film waveguides by mode conversion, Adv. Mater. Comm., 4, 795-798 (1992). 

Ashwell, G. J., Handa, T. and Ranjan, R., Improved second-harmonic generation from homomolecular Langmuir-Blodgett films of a transparent dye, J. Opt. Soc. Am., B, 15, 466-470 (1998). 

Ashwell, G. J., Walker, T. W., Leeson, P., Grummt, U. W. and Lehmann, F., Improved second-harmonic generation from Langmuir-Blodgett films, Langmuir, 14, 1525-1527 (1998). 

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