Multiple-Input Multiple-Output Enabled Large Bandwidth Density On-Chip Optical Interconnect

We propose to apply the multiple-input multiple-output (MIMO) from wireless communication to high density on-chip optical interconnect. MIMO makes it possible to reduce the waveguide pitch to subwavelength range and uses the crosstalk to improve system performance. The proposed N×N on-chip MIMO system consists of transmitter, high-density waveguides, homodyne coherent receivers, and electrical signal processing components. As an example, a 10×10 MIMO system with waveguide spacing of 250 nm is simulated. The possibility of data transmission at 10 Gb/s/channel from high-density waveguide array is numerically investigated. The minimum input optical power for the BER of 10-12 can reach -18.1 dBm. The BER is better than 10-12 when there is a phase shift of 73.5°. Compared to the conventional parallel waveguides with 2-μm pitch, the bandwidth density can be enhanced from 5 to 13.33 Gbit/μm/s at 10 Gb/s by using the MIMO techniques.