We present the theoretical analysis and design of a novel slotted photonic crystal geometry to demonstrate an on-chip Fano resonance. The device employs three parallel-coupled slotted photonic crystal cavities on an SOI wafer. We present a systematic analysis of the evolution of the Fano line-shape, while the geometric parameters of the structure and the inter-cavity distances vary. To achieve the dynamic tunability of the Fano resonance, we have considered an active electro-optic chromophore as the cover material of our slot-based geometry. This paves a novel way towards the demonstration of a fully-integrated, electrically-controllable Fano resonant geometry on a silicon-polymer platform.
We demonstrate the possibilities of atomic layer deposition technology to fabricate and improve the quality of nanowaveguide devices of a different kind in TiO2 platform. In particular, we present an original re-coating method of improving the quality of amorphous TiO2 strip waveguides, which reduces the propagation losses significantly. Then we demonstrate how atomic layer deposition technology makes it possible to fabricate very precise slot waveguides and to tune the geometrical parameters of nanobeam cavities operating with visible light. The main fabrication methods of the presented structures are electron beam lithography, reactive ion etching and atomic layer deposition.
A polarization independent band-pass filter is created by combining a silicon cross-slot waveguide and a Bragg grating cavity. By theoretically investigating different types of cavities we show how the sensitivity to polarization of the device can vary, and how we can strongly confine light in a two-dimensional slot waveguide. This kind of structure, where a slot waveguide, a photonic crystal and a nanowire waveguide are merged together, may find applications in the field of sensing. Indeed, a slight variation in the surrounding refractive index breaks the device symmetry. One polarization can thus be used to monitor the fluctuation of the other one. We describe here the principle of a Bragg grating merged with a cross slot waveguide in which a cavity is placed. We discuss the advantage of using different geometries of cavity and how this choice may affect the response of the device.
In this proceeding we are describing the optimization of a silicon slot waveguide coated with titanium dioxide deposited by Atomic Layer Deposition. In addition we show the characterization of a photonic crystal cavity directly patterned on a slot waveguide.