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

We design and experimentally demonstrate scalable 2 × 2, 4 × 4 and 8 × 8 silicon photonic (SiPh) thermo-optic switch exhibiting low loss, low crosstalk, low power penalty, and BER below 10
^-10
for payload data transmission. Less than 3.13 dB insertion loss (IL) and approximately 20.5 dB crosstalk is measured in the 8 × 8 SiPh banyan switch with thermal phase shifters. We also report on a semiconductor optical amplifier (SOA) in an indium phosphide (InP) technology platform with 25 dB gain and 7 dB noise figure enabling to transmit optical signals with large OSNR. Combining SiPh and InP technologies, we propose a lossless hybrid switch matrix with distributed SOA-based gain capable of transmitting data with near zero loss and low crosstalk over a large switching matrix. In hybrid SiPh/InP switches, the SOA gain compensates for the SiPh switch loss at the cost of amplified spontaneous emission (ASE) noise but mitigated by bandpass optical filters. Lower IL from the SiPh switch requires less gain from the SOAs leading to less OSNR degradation. Experimentally validated building blocks confirmed scalability up to 64 × 64 in SiPh-InP hybrid platform.