Absolute measurement of the quadratic nonlinear susceptibility of lithium niobate in waveguides

Efficiency measurements of second-harmonic generation in quasi-phase-matched lithium niobate waveguides yield a value for the nonlinear optical second-order susceptibility tensor element chi super(() sub(z) super(2) sub(z) super()) sub(z)(2 omega ; omega , omega ) = d sub(33) = (-20.6 plus or minus 2.1) pm/v in periodically poled, titanium-indiffused waveguides in congruent composition lithium niobate at room temperature for a fundamental wavelength of 1.52 mu m. A special fringe structure in the tuning curves was observed and explained as an unique feature in quasi-phase-matched parametric processes.