8 x 40 Gb/s WDM photonic integrated wavelength switch module for optical data center networks

We characterize the performance of a photonic integrated 1×8 WDM (8 channels Wavelength-Division Multiplexing) wavelength selective switch (WSS) module to realize a modular 8x8x8λ cross-connect switch. The module is based on SOA (Semiconductor Optical Amplifier) optical gates for nanoseconds wavelength and time switching operation. This technology enables the realization of low latency optical data center networks. Experimental measurements demonstrate a cross-talk lower than -35 dB, 11 dB/channel on chip gain and error-free operation at 40 Gb/s with limited penalty. The on chip gain and low cross-talk results presented in this study and the device proposed, being a scaled up version with double the channels of a previously demonstrated 4 x 4 modular architecture, validate the potentialities of this approach to scale up to an even larger channel number and hence port count.
Keywords: SOA (Semiconductor Optical Amplifier), PIC (Photonic Integrated Chip), DCN (Data Center Network), WSS (Wavelength Selective Switch).