Abstract: An optical system (20) provides a variable dispersion that helps to collect multi-spectral information on an object within the field of view. The system (20) includes at least two sets (24, 26) of optical elements (42x 42y, 44x, 44y) that have minimal deviation of a center wavelength and a non-zero deviation of at least one other wavelength. By rotating the sets of optical elements (24, 26) relative to one another or together, the degree of wavelength dispersion and the direction of the wavelength dispersion can be varied, respectively. By selectively rotating the sets of optical elements, the system also can be operated in a non-dispersed “white light” mode with no net dispersion at the image plane.

Abstract: A programmable reticle has a plurality of addressable pixels. Each of the pixels has one or more elastic elements which underlie a reflective surface, the elements each being activatable for selectively deforming part of the reflective surface. The amount of deformation is such that light reflected from a deformed part destructively interferes with light reflected from the vicinity of the deformed part. The programmable reticle may be used as a part of a scanning lithography system wherein a wafer or other device to be exposed is moved to expose different of its areas, while the pattern on the programmable reticle is changed to reflect the desired exposure pattern of the area of the wafer currently being exposed. In such a scanning system, any given point on the wafer will be exposed using a number of different pixels on the reticle; therefore the effect of a defective pixel will be “diluted” or “voted out” by the other, non-defective pixels also involved in exposing that spot.