Lossless Operation of an 8 × 8 SiPh/InP Hybrid Optical Switch

Abstract

We design a lossless 8 × 8 Silicon Photonics (SiPh)/Indium Phosphide (InP) hybrid optical switch. The design consists of an 8-channel InP gain block for coupling to an 8 × 8 thermally tuned Mach-Zehnder interferometer-based Banyan switch in a passive SiPh platform. The gain block is an array of eight 1300 μm-long semiconductor optical amplifiers (SOAs). We experimentally verified the InP gain block while the SiPh chip is accounted by replacing it with a loss component. The SOA in line with the optical signal path provides a net gain larger than 25 dB to compensate for the inherently large insertion loss of the 8 × 8 SiPh optical switch. The total energy consumption of the hybrid optical switch in lossless operation mode is 10.44 pJ/bit at 12.5 Gb/s.

Scalable SiPh-InP Hybrid Switch Based on Low-Loss Building Blocks for Lossless Operation

“…The 3 dB bandwidth of this switch is 25 nm. The performance of this switch is improved relative to than similar works [7], [8] enabling further scalability for greater port count. Payload transmission is then experimentally performed to demonstrate the switching performance using the setup in fig.…”

“…We use the SiPh switch presented in section II in the design of lossless scalable SiPh/InP hybrid switches. We have reported on employing an InP gain block, coupled to the SiPh switch, providing over 25 dB of optical gain in SiPh/InP hybrid switch [7]. The SOA optical gain comes with inevitable amplified spontaneous emission (ASE) noise degrading the optical signalto-noise ratio (OSNR) at the output of the hybrid switch.…”

“…Also, large gain from SOAs leads to non-linearity effects that degraded the payload integrity and increase the power penalty [9]. Furthermore, the sensitivity of the SOAs is limited (approximately to -20 dBm) [7]. As the switch radix increases, more than one gain blocks are needed to boost the signal power repeatedly, whereas, each gain block comes with inevitable coupling loss and fabrication cost.…”

“…In calculating the NF, we use the values presented in Table 1 for the SiPh on-chip loss. The NF of SOAs is 7 dB [7]. We equally distribute the SiPh loss and the InP gain between the first and the second stages.…”

“…We find the NF for two different scenarios: when the inter-chip coupling is budgeted 1.7 dB and 5 dB; and the filter loss is 0.5 dB and 3.5 dB, respectively. The NF of 4 × 4 and 8 × 8 switches are for the single stage gain hybrid switches presented in [14], [7]. Employing the distributed gain design, one can achieve lossless operation of 64 × 64 switch with NF below 30 dB.…”