Abstract: A reflection-based optical encoding apparatus for the detection of position and/or motion of a mechanical device includes an encoding medium having at least a first reflective portion, and an encoder housing having a light-emitting source and a light-detecting sensor embedded within, the encoder housing being placed in proximity to the encoding medium such that a functional light path can be established from the light-emitting source to the light-detecting sensor via the first reflective portion of the encoding medium. The encoder housing includes a first flat facet positioned between the light-emitting source and the encoding medium, the first flat facet having a first angle relative to a common geometric plane such that light passing from the light-emitting source to the encoding medium is refracted along a first angled path in a manner that the refracted light strikes a desired location of the encoding medium.