Efficient and tolerant chip-to-chip optical coupling via silicon nitride grating couplers

Abstract

An efficient and tolerant chip-to-chip optical coupling approach employing silicon nitride grating couplers was proposed and investigated. The integration of bottom mirrors and the strategic extension of grating length led to notable results, with a peak coupling loss of -0.28 dB and a 1-dB alignment tolerance along the x-axis reaching 25.4 μm when using a grating length of 50 μm.