Silicon subwavelength grating metamaterial (SGM), formed by periodically interleaving two or more types of materials a pitch far less than the operating wavelength, has been attracting substantial interest in recent years. It provides an effective approach to tailor the optical properties of naturally existing materials and thereby develop integrated photonic devices with unprecedented applications. In this paper, we introduce silicon photonics SGM waveguide based devices for optical interconnect and sensing applications. Silicon provides high index contrast and thus device footprints can be made very small. However, high index contrast is a double-edged sword, which also leads to a few devastating limitations such as limited photon-matter interaction and high dispersion. SGM waveguide can potentially resolve these issues. For instance, silicon-organic hybrid SGM modulator demonstrates < 44 GHz 6 dB bandwidth and estimated energy consumption of 2.55 fJ/bit. SGM waveguide based refractive index sensors show eminent improvement on the sensitivity compared to conventional strip waveguide based resonators. In the meantime, unlike evanescent wave based sensors, the surface sensitivity of SGM sensors does not decrease as analytes accumulate on the waveguide surface. SGM waveguide based passive components demonstrate improved bandwidth due to the decrease of waveguide dispersion. Other potential applications of SGM waveguide will also be discussed.
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