ABSTRACT
Optical emission from silicon is most practically accessible through nonlinear optical wave mixing, due to the indirect bandgap of the material. Although silicon is a material that absorbs visible light, third-harmonic generation driven by infrared signals can be used to generate visible light in silicon structures. In this work, we present a comprehensive investigation into third-harmonic generation in silicon-on-insulator waveguides. We demonstrate that few-micrometer length waveguides can be used to up-convert ultrafast 1550nm laser pulses to their third-harmonic with efficiencies up to ηTHG=2.8×10-5, the highest third-harmonic generation conversion efficiency reported to date in a silicon-based structure. Nonlinear propagation through 200µm long waveguides produces self-compressing temporal solitons, which dramatically broaden and blue shift the observed third-harmonic spectrum. Such devices are envisioned to provide a method for generating coherent visible signals within an integrated, CMOS compatible platform.
ABSTRACT
We propose a long-range magnetoplasmonic waveguide structure, based on cerium-substituted yttrium iron garnets, that is capable of achieving a useful π/2 nonreciprocal phase shift within one propagation length. Incorporating this plasmonic geometry into a Mach-Zehnder interferometer allows for the implementation of an efficient, integrable isolator scheme with an insertion loss of 2.51 dB and an extinction ratio of 22.82 dB. With a small footprint of 6.4×10(-3) mm(2) and nanoscale waveguide dimensions, we envision this device to be a key building block in the development of nanoplasmonic integrated circuitry.
