Advanced Material and Nanophotonic Approaches for Ultra-compact Electro-optic Modulators Open Access
Downloadable ContentDownload PDF
This thesis explores the fundamentals of increasing light matter interactions by combining plasmonics and novel active materials (Indium Tin Oxide and Graphene) toward Opto-electronic device applications. Here, surface plasmon polaritons play an important role in tightly confining the optical mode to a small volume. This phenomenon results in a tremendous increase of the field density in the area of interest, which provides an avenue to design wavelength scale ultra small electro-optic modulators. The material property of Indium Tin Oxide under different conditions was studied and reported. Alongside the fabrication and measurement of the Indium Tin Oxide modulator, grating coupler design and fabrication was studied. The grating coupler gave rise to the incorporation of on-chip circuitry from an off-chip source.Unlike Indium Tin Oxide or other bulk material, 2-D material Graphene displays a unique property where its in-plane permittivity can be tuned, while its out-of-plane permittivity remains the same. This material property makes it challenging to combine Graphene as an active material with the current plasmonic effect to increase the light matter interaction. To overcome this issue, a sub-wavelength slot waveguide structure was designed to greatly enhance the modulation depth of the Graphene modulator. Also, the interaction between current silicon photonic platforms and Graphene (or all 2-D material) was studied and mapped out.