Phase-matched second harmonic generation and cascaded nonlinearity in a Langmuir-Blodgett inverted waveguide of 2-docosylamino-5-nitropyridine

We discuss the results of our second harmonic generation (SHG) and nonlinear cascading experiments in organic waveguide. The waveguide is made of two identical Langmuir-Blodgett films with 2-docosylamino-5-nitropyridine. The thin film and waveguide characterization is presented with a detailed description of the experimental setup. An inverted waveguide is produced by a proper arrangement of the thin organic films. Using a tunable laser source the phase match at lambda =1063 nm of the SHG is proved. The SHG power-corrected efficiency of 8.9% W-1 was measured. The cascading of second-order nonlinearities is characterized by means of interferometric measurements which consist of detecting a nonlinear phase shift of the fundamental in dependence on input intensity. The measured value of cascading n(2) is 2.68x10(-13) cm(2)/W. (C) 2001 American Institute of Physics.