Large second-order optical nonlinearities in pulsed laser ablated silicon carbide thin films

The field of integrated optics is dependent on major advances in the development of new nonlinear optical (NLO) thin-film materials. NLO materials that are thermally stable and can be fabricated on a variety of substrates would offer vital gains in flexibility and cost. In this work, SiC thin films have been fabricated on sapphire, fused silica, and silicon substrates. The two optically transparent substrates result in films with large second-order optical nonlinearities, as large as 30 times the d₁₁ value of quartz. The refractory nature of SiC and its high melting point suggest that its robustness should compare favorably to organic NLO waveguide materials. The large NLO coefficients indicate that SiC may be competitive with currently available inorganic thin-film materials.