A spatial light modulator is disclosed, along with a method for making such a
modulator
that comprises an array of micromirror devices. The center-to-center distance and
the gap between adjacent micromirror devices are determined corresponding to the
light source being used so as to optimize optical efficiency and performance quality.
The micromirror device comprises a hinge support formed on a substrate and a hinge
that is held by the hinge support. A mirror plate is connected to the hinge via
a contact, and the distance between the mirror plate and the hinge is determined
according to desired maximum rotation angle of the mirror plate, the optimum gap
and pitch between the adjacent micromirrors.
In a method of fabricating such spatial light modulator, one sacrificial layer
is deposited on a substrate followed by forming the mirror plates, and another
sacrificial layer is deposited on the mirror plates followed by forming the hinge
supports. The two sacrificial layers are removed via the small gap between adjacent
mirror devices with spontaneous vapor phase chemical etchant. Also disclosed is
a projection system that comprises such a spatial light modulator, as well as a
light source, condensing optics, wherein light from the light source is focused
onto the array of micromirrors, projection optics for projecting light selectively
reflected from the array of micromirrors onto a target, and a controller for selectively
actuating the micromirrors in the array.