Patent attributes
Photonic integrated circuit (PIC) chips with backside vertical optical coupler and packaging into an optical transmitter/receiver. A grating-based backside vertical optical coupler functions to couple light to/from a plane in the PIC chip defined by thin film layers through a bulk thickness of the PIC chip substrate to emit/collect via a backside surface of the PIC chip where it is to be coupled by an off-chip component, such as an optical fiber. Embodiments of a grating-based backside vertical optical coupler include a grating coupler with a grating formed in a topside surface of the thin film A reflector is disposed over the grating coupler to reflect light emitted from the grating coupler through the substrate to emit from the backside of the PIC chip or to reflect light collected from the backside of the PIC chip through the substrate and to the grating coupler.