A sensor assembly having an optical fiber, a lens in optical communication with the optical fiber, a reflective surface spaced from the lens, for reflecting light from the beam back to the lens, a partially reflective surface positioned between the reflective surface and the lens, the partially reflective surface for reflecting light from the beam back to the lens, and an alignment device for aligning the lens and reflective surface with respect to one another, such that light from the beam of light transmitted from the lens reflects from the reflective surface back to the lens. The alignment device can have a rotational component and a base component, where the rotational component rotates to align a beam of light transmitted from the lens. The rotational component can also cooperate with the base component to move axially with respect to the reflective surfaces to align the beam for optimum power.