Design and fabrication of a compact chip-scale optical cross-connect enabled by photonic crystals for optical interconnects.

摘要

As integrated circuits, such as microprocessors, are fabricated with higher yields and with increasing numbers of smaller and smaller transistors, the communication between discrete elements becomes as important as the elements themselves. The delays associated with signal distribution across the chip have become a limiting factor for processor speeds, and are primarily located within the global interconnect layers for intra-chip and inter-chip communication. Optical interconnects have the potential to relieve the restrictions set by the interconnect bottleneck by taking advantage of their reduced power demands for signal distribution and their lower propagation delays. The work within this dissertation discusses the design, fabrication and characterization of an ultra-compact photonic crystal optical switch for use within a transparent optical cross-connect (OXC). To reduce the size and power consumption of the switch, perturbations were made within the photonic crystal structure to achieve a degree of slow light, decreasing the group velocity of the propagating signals. Further, as a means to integrate the developed switch matrix to a microprocessor in order to serve as a chip's optical global interconnect, a process was developed to transfer the switch fabric to a new substrate as a silicon-nanomembrane (Si-NM). The developed transfer process allows the transfer and stacking of intricate photonic devices, such as the aforementioned switch matrix, to new material platforms and substrates that would be incompatible with typical complementary-metal-oxide-semiconductor CMOS processing. The developed Si-NM processing along with the developed switch matrix for a transparent OXC are significant steps toward implementing an optical interconnect network on a chip.