Enhancing second-order optical processes in Si-compatible materials is important for the demonstration of innovative functionalities and nonlinear optical devices integrated on a chip. Here, we demonstrate significantly enhanced Second-Harmonic Generation (SHG) by silicon-rich silicon nitride materials over a broad spectral range, and show a maximum conversion efficiency of 4.5 x 10-6 for sub-stoichiometric samples with 46 at. % silicon. The SHG process in silicon nitride thin films is systematically investigated over a range of material stoichiometry and thermal annealing conditions. These findings can enable the engineering of innovative Si-based devices for nonlinear signal processing and sensing applications on a Si platform.
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Generation of second harmonic radiation from sub-stoichiometric silicon nitride thin films
E. F. Pecora, A. Capretti, G. Miano, L. Dal Negro
Applied Physics Letters 102, 141114 (2013)