A wavelength selective switch , comprising: an optical port array having a first plurality of ports extending in a first plane for receiving optical beams and a second plurality of ports extending in a second plane for receiving optical beams, an offset axis extending through both the first and second planes, the ports in the first plurality of ports being laterally displaced from the ports in the second plurality of ports along the offset axis; a dispersion element receiving a first of the optical beams from one of the first plurality of ports and a second of the optical beams from the second plurality of ports and spatially separating the optical beams into respective first and second pluralities of wavelength components along first and second wavelength dispersion axes, the first plurality of ports having optical axes extending along a first direction and the second plurality of ports having optical axes extending along a second direction, the first and second directions being different from one another, at least one of the first and second directions being non-orthogonal to a port axis that extends in a plane parallel to at least one of the first and second planes; a focusing element for focusing the first and second pluralities of wavelength components; and a programmable optical phase modulator for receiving the focused plurality of wavelength components, the modulator being configured to steer the wavelength components received from any one of the first plurality of ports to a selected one of the first plurality of ports and being further configured to steer the wavelength components received from any one of the second plurality of ports to a selected one of the second plurality of ports . an optical port array having a first plurality of ports extending in a first plane for receiving optical beams and a second plurality of ports extending in a second plane for receiving optical beams, an offset axis extending through both the first and second planes, the ports in the first plurality of ports being laterally displaced from the ports in the second plurality of ports along the offset axis; a dispersion element receiving a first of the optical beams from one of the first plurality of ports and a second of the optical beams from the second plurality of ports and spatially separating the optical beams into respective first and second pluralities of wavelength components along first and second wavelength dispersion axes, the first plurality of ports having optical axes extending along a first direction and the second plurality of ports having optical axes extending along a second direction, the first and second directions being different from one another, at least one of the first and second directions being non-orthogonal to a port axis that extends in a plane parallel to at least one of the first and second planes; a focusing element for focusing the first and second pluralities of wavelength components; and a programmable optical phase modulator for receiving the focused plurality of wavelength components, the modulator being configured to steer the wavelength components received from any one of the first plurality of ports to a selected one of the first plurality of ports and being further configured to steer the wavelength components received from any one of the second plurality of ports to a selected one of the second plurality of ports . <EOS>