Performance of ring-resonator based optical backplane in high capacity routers

Abstract

The use of architectures that implement optical switching without any need of optoelectronic conversion allows us to overcome the limits imposed by today's electronic backplane, such as power consumption and dissipation, as well as power supply and footprint requirements. We propose a ring-resonator based optical backplanes for router line-card interconnections. In particular we investigate how the feasibility of the architecture is affected by the following parameters: number of line cards, switching-element round-trip losses, frequency drifting due to thermal variations and waveguide-crossing effects. Moreover, to quantify the signal distortions introduced by filtering operations, the noiseless eye diagrams for the different parameter conditions are shown in case of an onoff keying non-return-to-zero input signal at 10 Gb/s.

Optical Backplane Based on Ring-Resonators: Scalability and Performance Analysis for 10 Gb/s OOK-NRZ

“…In the proposed architecture, the FSR of RRs in RSC drives the choice of the technology to be used (see Design Section). As for the PSC of our reference architecture (32 chann./50 GHz, 2 stages), the FSR of last-stage RR is 200 GHz while for the RSC, the FSR of each RR is 1.6 THz, corresponding to rings with radius = 7 µm, thus, the choice of silicon becomes mandatory [7]. Smaller rings, that is, wider FSR, are difficult to achieve in practice.…”

“…In our work, (1) we propose a backplane fabric made of a cascaded RR; (2) we introduce a new methodology for scalability analysis based on accurate transfer function evaluation; and (3) we confirm the feasibility of the architecture via analysis of the bit error rate (BER) for transmission of an On-Off Keying (OOK) Non-Return-to-Zero (NRZ) signal at 10 Gb/s. This work is an extension of [7], in which BER analysis was not available. Our procedure goes beyond the simple power budget and Cross-Talk (XT) analyses since it accounts for waveguide dispersion effects, which may have a non-negligible impact in all-optical backplanes.…”