Silicon waveguide as virtual photonic bandgap structure array for realizing compact optical filters

ABSTRACT

An engineered silicon rib waveguide on Silicon-On-Insulator platform which can act as virtual photonic bandgap structure is proposed. Selective periodic etching of materials from a rib waveguide is done to create a periodic rib-ridge structure. Each of the rib-ridge sections will therefore have different effective refractive indices and will act as virtual multilayered periodic structure or one-dimensional photonic bandgap structure. Their spatial positions and widths can be controlled to realize different type of photonic filters for integrated photonics applications. Realization of narrowband, multi-band and band-pass filter are shown here. These types of waveguide based monomaterial optical filters avoid the challenges generally faced while fabricating multilayer structures of different heterogeneous materials having different refractive indices. Moreover, as the device is waveguide based, its size is very small and will be useful for compact integrated photonics.

KEYWORDS:

• Silicon-on-Insulator
• rib waveguide
• photonic bandgap structure
• optical filters
• C band communication
• WDM technologies

Disclosure statement

No potential conflict of interest was reported by the author(s).