Patent ID: 7233029

Claim:
A spatial light modulator comprising: a support substrate that has an electrode layer; and a movable thin film that has at least an electrode layer, said movable thin film being opposingly placed above said support substrate with being separated by a predetermined gap distance in a manner that said movable thin film is flexurally deformable toward said support substrate, wherein a predetermined driving voltage is applied between said electrode layer of said support substrate and said electrode layer of said movable thin film to cause said movable thin film to be deflected toward said support substrate by an electrostatic force acting between said electrode layers, whereby optical characteristics of said device with respect to incident light are changed to perform light modulation on the incident light, wherein an optical functional film having a plurality of stacked films is disposed on each of sides of said movable thin film and said support substrate, said sides being opposed to each other, and said optical characteristics are optical interference characteristics corresponding to the gap distance between said movable thin film and said support substrate, and a wavelength of the incident light, wherein the plurality of stacked films are formed of SiNx, and refractive indices of adjacent ones of the plurality of films are different from each other, and wherein stresses of prescribed ones of the plurality of films of the multilayer film have opposite signs with respect to adjacent ones of the plurality of films.