Patent ID: 8035885

Claim:
A tri wavelength diffracting modulation (TWDM) element comprises: a first set of movable reflective rigid plates, a second set of movable reflective rigid plates, a first set of top reflective surfaces topped with the first set of movable reflective rigid plates, and a second set of top reflective surfaces topped with the second set of movable reflective rigid plates, wherein the first set of top reflective surfaces and the second set of top reflective surfaces are both configured parallel to a top reference plane and have equal reflection to incident electromagnetic radiation of a defined spectrum in a first direction 1 ; wherein the first set of movable reflective rigid plates and the second set of movable reflective rigid plates are adapted to be both placed at a zero position where the first set of top reflective surfaces and the second set of top reflective surfaces are kept at a zero distance relative and parallel to the top reference plane; wherein the first set of movable reflective rigid plates is adapted to be displaced to a first position while keeping the first set of top reflective surfaces latched at a first vertical distance from but parallel to the top reference plane; and the second set of movable reflective rigid plates is adapted to be displaced to a second position while keeping the second set of top reflective surfaces latched at a second vertical distance from but parallel to the top reference plane; and wherein the first vertical distance is equal to m*λ 1 /4, the second vertical distance is equal to n*λ 2 /4, and absolute difference between the first vertical distance and the second vertical distance is equal to p*λ 3 /4, where the λ 1 , λ 2 and λ 3 are first, second and third distinguished wavelengths within the defined spectrum of the incident electromagnetic radiation, and m, n and p are odd integers.