An optical interposer comprising: (a) a crystalline substrate having a top planar surface and a crystalline plane angle; (b) a groove defined in the top planar surface and extending from an edge of the substrate to a terminal end, the groove having side walls and a first facet at the terminal end, the facet having a first angle relative to the top planar surface, the first angle being about the crystalline plane angle, the first angle having a delta from 45°; (c) a reflective coating on the first facet; and (d) an optical conduit having an optical axis and an end face optically coupled with the first facet, the end face having a second angle with respect to the optical axis such that the angle of refraction at the end face compensates for the delta such that the end face and the first facet cooperate to bend light about 90°.