Applications of subwavelength grating structures in silicon-on-insulator waveguides
2010
We discuss several applications of both resonant and non-resonant subwavelength gratings (SWGs) for silicon
photonics. We present results of evanescent field molecular sensing using the transverse magnetic mode of a 0.22 μm
thick silicon slab waveguide with a resonant SWG, which couples a free space laser beam to the silicon waveguide
mode. The optical readout of this configuration is almost identical to the established surface plasmon resonance sensing
technology. Using calibrated sucrose solutions, we demonstrate a bulk refractive index sensitivity of 111 nm/RIU in
good agreement with rigorous coupled wave analysis calculations. The binding of a monolayer of streptavidin protein on
the waveguide surface is monitored in real time with a signal-to-noise ratio of ~500. In another application, non-resonant
SWGs are used to create effective dielectric media with a refractive index that can be tuned between the values of silicon
(3.48) and SU-8 polymer used for the cladding (1.58). For example, we present SWG waveguides with an effective core
index of approximately 2.65, which exhibit lower propagation loss than photonic wire waveguides of similar
dimensions. We use these SWG waveguides to demonstrate highly efficient fiber-chip couplers.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
6
References
9
Citations
NaN
KQI