Presenter: Peter Girouard. Abstract: All-optical signal processing is expected to contribute significantly toward increasing the throughput of next generation ...
Title: Deuterium Passivated Amorphous Silicon on Insulator: A Robust Nonlinear Photonic Platform Presenter: Peter Girouard Abstract: All-optical signal processing is expected to contribute significantly toward increasing the throughput of next generation telecommunication networks. To fully exploit the possibilities, realization of efficient Kerr nonlinearities in an integrated platform is required. Amorphous silicon (a-Si) is a promising candidate which has a growth-dependent bandgap that can be tuned to minimize nonlinear absorption while simultaneously maintaining a nonlinearity that is larger than that of any other CMOS compatible material; its stability under illumination at telecommunication wavelengths, however, is dependent on the film growth procedure and not well understood. Here, we demonstrate a method to stabilize the a-Si platform by borrowing techniques employed elsewhere to enhance its stability: passivation with deuterium. We describe two plasma enhanced chemical vapor deposition growth methods which we have implemented to fabricate a-Si films with tunable deuterium content, refractive index, and bandgap. We use power and time dependent insertion loss measurements of waveguides to demonstrate the evolution of hysteretic loss in hydrogenated a-Si and its absence in deuterated a-Si. Finally, we show that both the short carrier lifetime and high nonlinearity – important properties for nonlinear platforms – are left intact by the deuteration.
