Laser diodes emit a highly divergent beam with elliptical intensity profile and astigmatic wavefront. Conventional high quality collimators use up to seven elements to produce a plane wavefront free from astigmatism and with circular intensity profile. The same task can be accomplished by a system of only two holographic optical elements (HOE). Because of the strong dispersion of diffractive elements, it is necessary to achromatize the system. The design is based on Weingartner's iteration. The design algorithm and optical properties of the system are discussed.