Nonlinear optical studies of 3-methyl-4-methoxy-4 '-nitrostilbene single-crystal films

We report the second-order optical measurement of single-crystal thin-films of 3-methyl-4-methoxy-4'-nitrostilbene by transverse second-harmonic gener ation (SHG) technique. Phase mismatch was negligible in the measurements si nce the thickness of the films was less than the coherence length. Detailed polarization selective measurements were used to determine the magnitudes of the tensor elements of second-order susceptibility. The values of d coef ficients at the fundamental wavelength of 1064 nm were measured to be d(33) =195 +/- 10 pm/V and d(24)=75 +/- 5 pm/V. Both type I and type II phase-mat ched propagation directions were identified in the crystal and the type II phase matching direction lies parallel to the film. The results show that t hese films are promising for applications such as phase-matched SHG in wave guides. (C) 2000 American Institute of Physics. [S0003-6951(00)03132-6].