CUED Publications database

Nonlinear optics in Silicon photonic crystal cavities

Andreani, LC and Andrich, P and Galli, M and Gerace, D and Guizzetti, G and Lo Savio, R and Portalupi, SL and O'Faolain, L and Reardon, C and Welna, K and Krauss, TF (2011) Nonlinear optics in Silicon photonic crystal cavities. International Conference on Transparent Optical Networks.

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Silicon is known to be a very good material for the realization of high-Q, low-volume photonic cavities, but at the same it is usually considered as a poor material for nonlinear optical functionalities like second-harmonic generation, because its second-order nonlinear susceptibility vanishes in the dipole approximation. In this work we demonstrate that nonlinear optical effects in silicon nanocavities can be strongly enhanced and even become macroscopically observable. We employ photonic crystal nanocavities in silicon membranes that are optimized simultaneously for high quality factor and efficient coupling to an incoming beam in the far field. Using a low-power, continuous-wave laser at telecommunication wavelengths as a pump beam, we demonstrate simultaneous generation of second- and third harmonics in the visible region, which can be observed with a simple camera. The results are in good agreement with a theoretical model that treats third-harmonic generation as a bulk effect in the cavity region, and second-harmonic generation as a surface effect arising from the vertical hole sidewalls. Optical bistability is also observed in the silicon nanocavities and its physical mechanisms (optical, due to two-photon generation of free carriers, as well as thermal) are investigated. © 2011 IEEE.

Item Type: Article
Divisions: Div B > Photonics
Depositing User: Cron Job
Date Deposited: 17 Jul 2017 19:24
Last Modified: 03 May 2018 02:11