An optics system is provided that is made up of a single diffractive optical element that performs beam collimating, beam splitting, and light blocking functions. The diffractive optical element is made up of a substrate having a first surface comprising an entrance facet and a second surface comprising an exit facet. The first surface comprising the entrance facet performs at least the functions of collimating the beam of light produced by the light source and of tilting the collimated beam in a particular direction. The second surface comprising the exit facet performs at least the functions of splitting the tilted collimated beam into at least two collimated light beams and of blocking unintended light (i.e., one or more mode order groups that are not intended to be used for imaging purposes). By performing all of these functions on different surfaces of a single substrate, an extremely compact optics system having very high optical efficiency and a very high signal-to-noise ratio is realized.