Grating coupler for inter-chip optical coupling

摘要

A photonic integrated circuit (PIC) that includes an optical source that provides an optical signal having a wavelength is described. This optical source includes a reflecting layer, a bottom cladding layer, an active layer (such as a III-V semiconductor) having a bandgap wavelength that exceeds that of silicon, and a top cladding layer. Moreover, an optical coupler (such as a grating coupler) that couples the optical signal out of a plane of the active layer is included in a region of the active layer. In this region, the top cladding layer is absent. Furthermore, in an adjacent region, the top cladding layer includes an inverse taper so that the top cladding layer is tapered down from a width distal from the region. In conjunction with the optical coupler, the inverse taper may facilitate low-loss optical coupling of the optical signal between the PIC and another PIC.

主权项

1. A photonic integrated circuit (PIC), comprising:
a substrate; a bottom cladding layer disposed on the substrate; an active layer, disposed on the bottom cladding layer, having a bandgap wavelength that exceeds that of silicon; a top cladding layer disposed on the active layer, wherein the bottom cladding layer, the active layer and the top cladding layer constitute an optical source that provides an optical signal having a wavelength; and an optical coupler, disposed in a first region of the active layer, configured to couple the optical signal out of a plane of the active layer; wherein the top cladding layer is absent above the optical coupler in the first region; and wherein, in a second region proximate to the first region, the top cladding layer includes an inverse taper so that a width of the top cladding layer is tapered down from a width in a third region distal from the first region.