Chip-to-chip optical interconnect using gold long-range surface plasmon polariton waveguides

Area of Science:

• Photonics and Materials Science
• Integrated Optics
• Nanophotonics

Background:

• Chip-to-chip communication faces bandwidth limitations with traditional electrical interconnects.
• Optical interconnects offer a solution for high-speed data transfer in advanced computing systems.
• Surface plasmon polaritons (SPPs) enable light manipulation at the nanoscale.

Purpose of the Study:

• To demonstrate a novel on-board chip-to-chip optical interconnect.
• To utilize long-range surface plasmon polariton (LR-SPP) waveguides for signal transmission.
• To evaluate the performance of LR-SPP waveguides for high-speed optical interconnections.

Main Methods:

• Fabrication of LR-SPP waveguides using 2.5-cm-long gold strips in a polymer cladding.
• Excitation of the fundamental LR-SPP mode using a TM-mode vertical-cavity surface-emitting laser (VCSEL) at 1.3 microm.
• Optimization of waveguide width (1.5-5.0 microm) to minimize insertion loss.
• Assembly of a 4-channel array interconnect system with optoelectronic chips.

Main Results:

• A 3-microm-wide waveguide achieved a minimum insertion loss of -17 dB.
• The insertion loss comprised 6 dB/cm propagation loss and 2 dB coupling loss.
• Demonstrated 10 Gbps total data transmission (2.5 Gbps per channel) using a 4-channel array.
• Validated the feasibility of LR-SPP waveguides for optical interconnection.

Conclusions:

• LR-SPP waveguides are a viable technology for on-board chip-to-chip optical interconnects.
• The demonstrated system shows potential for high-bandwidth, low-loss optical data transfer.
• This research paves the way for next-generation optical communication in electronic systems.