A miniature module emits and focuses a divergent light beam. The focusing module consists of a small-sized light emitter, such as a laser diode, and a micro-optical element seated in a lens holder. The outside diameter of the micro-optical element is 4 mm or less and preferably less than or equal to 2.5 mm. The micro-optical element may be a small conventional lens, a gradient index lens, or one of several types of diffractive optical element. The focal length of the module relative to the light from the emitter is set by sliding the lens holder along its central axis and permanently adhering it in place with respect to the emitter after focusing. During focal adjustment, axial rotation between the lens holder and between the base of the emitter is prevented by a series of notches. The miniature focusing module is smaller, lighter, costs less and may provide a larger relative aperture than the conventional structures currently used for example in solid state laser scanners.