Optical arrangement for suppressing outerband crosstalk in a wavelength selective switch

An optical device, comprising:

• at least three optical ports;
• an optical arrangement for arranging an optical beam received from any of the optical ports into a first polarization state;
• a dispersion element for spatially separating the optical beam into a plurality of wavelength components;
• an optical power element for converging each of the plurality of wavelength components in at least one direction;
• and
• a programmable optical phase modulator for receiving the focused plurality of wavelength components in the first polarization state, the modulator being configured to steer the wavelength components through the optical arrangement, the dispersion element and the focusing element to a selected one of the optical outputs, the programmable optical phase modulator including an active area that performs the steering and a non-active area surrounding the active area;
• and
• a polarizing arrangement located in an optical path between at least one of the optical ports and at least a portion of the non-active area of the programmable optical phase modulator, the polarizing arrangement being configured to arrange optical energy into a second polarization state orthogonal to the first polarization state.