Patent ID: 7831115

Claim:
An apparatus, comprising: a package substrate comprising a package substrate core, a dielectric layer coupled with the package substrate core, and one or more input/output (I/O) optical fibers coupled with the package substrate core or coupled with the dielectric layer, or a combination thereof, the one or more I/O optical fibers to guide I/O optical signals to and from the package substrate and to allow both input and output optical signals to travel through the one or more I/O optical fibers, the one or more I/O optical fibers comprising a first core and a second core, the first core comprising an input signal pathway and the second core comprising an output signal pathway, the one or more I/O optical fibers comprising a first core cladding material coupled with the first core and a first buffer coupled with the first core cladding materials, the first core cladding material and the first buffer materials being disposed between the first core and the second core, and the first core comprising a central structure of the one or more I/O optical fibers and the second core comprising a structure that surrounds the first core.