Multicore Fiber Optimization for Application to Chip-to-Chip Optical Interconnects

We present the design of a holey microstructured multicore optical fiber optimized to meet the stringent requirements of chip-to-chip optical interconnects, namely, be compatible with high-speed vertical-cavity surface-emission lasers, feature ultrahigh channel density, low crosstalk, and millimeter-bend resistance to sustain the tight bends required on an electronic circuit board. We show that the shortcomings of the standard hexagonal microstructure can be overcome by the use of seven-rod cores. We present the detailed simulation results of the crosstalk and bend loss as a function of all the important microstructure parameters that led to the optimized solution. We discuss the crosstalk dependence on the bending radius. To our knowledge, the multicore fiber presented here achieves the highest normalized core density proposed to date, low enough crosstalk for meter-long transmission at 10 Gb/s and bend loss <; 0.02 dB/loop at a 1-mm bend radius. Maximizing space-division multiplexing, it has the potential to allow Tb/s·cm² optical interconnects without the need for wavelength-division multiplexing.