Polarization- and Temperature-Insensitive 8x400GHz O-Band Cascaded AWG for Large Radix Data Center and AI/ML Networks

We demonstrate a PLC-based O-Band 8-channel cascaded AWG design. The manufactured prototypes achieve 400 GHz channel spacing while simultaneously reaching a 1 dB bandwidth of 300 GHz and a crosstalk below −40 dB. The measured fiber-to-fiber loss is as low as 2.7 dB and the PDL is below 0.2 dB. We determine a low thermal drift of -1.8 GHz/Kelvin. The combination of low IL, high bandwidth, low crosstalk, and low thermal drift make the device particularly attractive for WDM-based data center and AI networks architectures that benefit from a large network switch radix.