Optical I/O system using planar light-wave integrated circuit
Photonic components are placed on the processor package to bring the optical signal close to the processor die. The processor package includes a substrate to which the processor die is coupled, and which allows the processor die to connect to a printed circuit board. The processor package also includes transceiver logic, electrical-optical conversion circuits, and an optical coupler. The electrical-optical conversion circuits can include laser(s), modulator(s), and photodetector(s) to transmit and receive and optical signal. The coupler interfaces to a fiber that extends off the processor package. Multiple fibers can be brought to the processor package allowing for a scalable high-speed, high-bandwidth interconnection to the processor.
1. A processor comprising:
a package substrate;
a processor die coupled to the package substrate; and
a planar light-wave circuit (PLC) coupled to the processor die on the package substrate, the PLC including
electrical-optical circuits coupled through the PLC using through-silicon vias (TSVs) to transceiver logic on the package substrate, the electrical-optical circuits to convert between an electrical signal and a corresponding optical signal, wherein the electrical-optical circuits include a laser to produce light and a transceiver to generate the optical signal using the light, and
an optical coupler coupled through the PLC using through-silicon vias (TSVs) to the package substrate and coupled to the electrical-optical circuits to transfer the optical signal between the electrical-optical circuits and an optical fiber that extends off of the processor,
wherein the optical coupler is integrated to the PLC using an interface including a mirror to redirect the optical signal from the PLC to the optical coupler.
2. The processor of claim 1 , wherein at least part of the PLC is integrated into the package substrate.
3. The processor of claim 1 , wherein the transceiver includes a transceiver logic chip disposed on the PLC.
4. The processor of claim 1 , wherein the processor die includes transceiver logic integrated onto the processor die.
5. The processor of claim 1 , wherein the electrical-optical circuits include waveguide elements integrated into the PLC.
6. The processor of claim 1 , wherein the optical coupler comprises a two-dimensional lens array.
7. The processor of claim 1 , wherein a first wave guide extends from the transceiver to the interface along the PLC and provides the optical signal to the mirror which reflects the optical signal away from the PLC and into the optical coupler.
8. The processor of claim 7 , wherein a second wave guide extends from the laser to the transceiver to provide the light to the transceiver.
9. The processor of claim 1 , wherein the transceiver includes a drive modulator to generate the optical signal from the light and the interface includes a mode expander to change a spot size of the optical signal.