McMaster University

Purpose

Silicon nitride is becoming established as an important nanophotonic platform because of its compatibility with CMOS fabrication and its substantially broader spectral transparency range compared to silicon. Silicon nitride allows CMOS integrated photonics to break into new application areas, in particular sensing in the visible and mid-IR spectral ranges, quantum photonics and nonlinear optics. However, silicon nitride poses some fundamental challenges. The high index contrast, which allows device miniaturization, causes significant optical scattering losses, mode size disparity between optical fiber and on-chip waveguides results in high coupling losses, and fabrication tolerances are tight, making manufacturing yield a major concern. Subwavelength engineering was successfully used to overcome similar challenges in silicon waveguides and we believe that this strategy can also be advantageously implemented in the silicon nitride platform, which has not yet been done. In this proposed New Beginnings project, the benefits of subwavelength metamaterial engineering for the emerging nitride nanophotonic platform will be demonstrated. This can result in major advances in state-of-the-art silicon nitride integrated devices, including new photonic sensors, next generation quantum communications chips and on-chip optical amplifiers for telecom applications.