2-d diffraction grating for substantially eliminating polarization dependent losses

Abstract

A 2D diffraction grating light valve modulates an incident beam of light. A plurality of elements each have a reflective surface with their respective reflective surfaces substantially coplanar. Alternatively, the reflective surfaces of the plurality of elements lie within one or more parallel planes. The elements are supported in relation to one another. Preferably, a planar member includes a plurality of holes arranged in a symmetrical two-dimensional array and configured such that the holes substantially optically extend the elements. Alternatively, one or more elements substantially optically extends the plurality of holes. The planar member includes a light reflective planar surface that is parallel to the plane of the elements within a functional area of the device. The planar member is supported in relation to the elements. By applying an appropriate biasing voltage to the planar member, the planar member can be moved in a direction normal to the plane of the elements. When the planar member and the plurality of elements are in a first configuration, the 2D diffraction grating reflects the incident beam of light as a plane mirror. When the planar member and the plurality of elements are in a second configuration, the 2D diffraction grating diffract the incident beam of light. Preferably, the planar member is a membrane circumferentially coupled to a support structure.