Generation of a sum-frequency wave in a microscopic optically nonlinear waveguide made of lithium niobate

Sum-frequency waves were generated when a microscopic optically nonlinear waveguide made of lithium niobate was excited with neodymium (λ=1.06 μ) and helium-neon (λ=1.152 μ) lasers. Moreover, the second harmonic of the neodymium laser radiation was generated. A study was made of two waveguides, which were 0.98 and 2.36-μ thick. The wave-delay coefficients and the conversion efficiency were determined.