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arXiv · 1409.7810

Dispersion engineered silicon nitride waveguides by geometrical and refractive-index optimization

J. M. Chavez Boggio·D. Bodenmueller·T. Fremberg·R. Haynes·M. M. Roth·R. Eisermann·M. Lisker·L. Zimmermann·M. Boehm
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Abstract

Dispersion engineering in silicon nitride (SiX NY ) waveguides is investigated through the optimization of the waveguide transversal dimensions and refractive indices in a multi-cladding arrangement. Ultra-flat dispersion of -84.0 +/- 0.5 ps/nm/km between 1700 and 2440 nm and 1.5 +/- 3 ps/nm/km between 1670 and 2500 nm is numerically demonstrated. It is shown that typical refractive index fluctuations as well as dimension fluctuations during the fabrication of the SiX NY waveguides are a limitation for obtaining ultra-flat dispersion profiles. Single- and multi-cladding waveguides are fabricated and their dispersion profiles measured (over nearly 1000 nm) using a low-coherence frequency domain interferometric technique. By appropriate thickness optimization, the zero-dispersion wavelength is tuned over a large spectral range in both single-cladding waveguides and multi-cladding waveguides with small refractive index contrast (3 %). A flat dispersion profile with 3.2 ps/nm/km variation over 500 nm is obtained in a multi-cladding waveguide fabricated with a refractive index contrast of 37 %. Finally, we generate a nearly three-octave supercontinuum in this dispersion flattened multi-cladding SiX NY waveguide.

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J. M. Chavez Boggio, D. Bodenmueller, T. Fremberg, R. Haynes, M. M. Roth, R. Eisermann, M. Lisker, L. Zimmermann, M. Boehm. 2014-09-27. Dispersion engineered silicon nitride waveguides by geometrical and refractive-index optimization. https://doi.org/10.1364/josab.31.002846

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