MEMS wavelength-selective switch incorporating liquid crystal shutters for attenuation and hitless operation

We present the technological merits of combining a high fill factor, one-dimensional, MEMS micro-mirror array for switching and liquid crystal shutters for amplitude control within a wavelength-selective switch (WSS). The combination allows for simplified MEMS actuator design, support for high port counts, high attenuation accuracy, high natural frequency, mechanical robustness against shock & vibrations, and fast switching times. The complexity associated with dual modulating elements at the focal plane is addressed by design choices and optimization of the depth of focus. The WSS is fully Telcordia qualified and carrying live traffic in deployed networks.