DEFORMABLE GRATING APPARATUS INCLUDING STICTION PREVENTION MEANS

摘要

A modulator for modulating incident light, the modulator comprising a plurality of equally spaced elements (116), each including a light reflective planar surface. The elements are parallel to each other with their light reflective surfaces parallel to each other. The modulator includes means for moving the elements relative to one another between a first configuration wherein the modulator reflects the incident light as a plane mirror, and a second configuration wherein the modulator diffracts the incident rays of light as they are reflected. At least one of the facing surfaces (114) (110) of the elements and underlying substrate (108) is configured to reduce any tendency to stick as they are pulled together. The light reflective surfaces of the elements remain parallel to each other in both the first and the second configurations and the perperdicular spacing between the reflective surfaces of adjacent elements is equal to m/4 times the wavelength of the incident light, wherein m = an even whole number or zero when the elements are in the first configuration and m = an odd number when the elements are in the second configuration.