Reconfigurable port arrays for wavelength selectable switch

A reconfigurable polarization rotator array comprising:

• a plurality of liquid crystal (LC) microcells, each individual LC microcell separately addressable by a control voltage input to provide one of 90° polarization rotation and 0° polarization rotation, the plurality of LC microcells all exhibiting a same width W less than ten microns;
• a plurality of control electrodes coupled to the plurality of LC microcells in a one-to-one relationship;
• and
• a window configuration controller coupled to the plurality of control electrodes and responsive to window reconfiguration commands to apply appropriate voltages to each control electrode of the plurality of control electrodes to define selected groups of adjacent microcells to form a transmission window and provide a predetermined polarization rotation to an optical beam passing through the transmission window.

A reconfigurable wavelength selective switch, comprising:

• a plurality of N ports for receiving and transmitting optical signals of predetermined wavelengths;
• a switch engine for controlling the connection between input ports and output ports within the plurality of N ports;
• and
• a reconfigurable port interface disposed between the plurality of N ports and the switch engine, including
• a birefringent walk-off plate disposed adjacent to the plurality of N ports, the birefringent walk-off plate performing spatial separation of orthogonal polarizations of an optical input signal and spatial recombination of parallel polarizations of an optical output signal;
• and
• a polarization rotator array positioned to intercept optical signals exiting and entering the birefringent walk-off plate, the polarization rotator array including a plurality of LC microcells, each individual LC microcell separately addressable by a control voltage input to provide one of 90° polarization rotation via a first applied voltage, and 0° polarization rotation via a second applied voltage, and a plurality of control electrodes coupled to the plurality of LC microcells in a one-to-one relationship, wherein first selected groups of adjacent LC microcells are held at the first applied voltage to configure a 90° polarization window and second selected groups of adjacent LC microcells are held at the second applied voltage to configure a 0° polarization window, defining a specific port arrangement of the reconfigurable wavelength selectable switch, the number of individual LC microcells forming the first and second groups selected to define a window size for the defined specific port arrangement.