The present disclosure provides an apparatus (100) that can include a first housing (110) and a second housing (120) rotationally coupled to the first housing where the second housing rotates with respect to the first housing about an axis of rotation (170). The apparatus can also include an optical transmitter (130) coupled to the first housing where the optical transmitter can be configured to transmit light. The apparatus can further include a lightguide (140) including a first lightguide end (144) substantially at the axis of rotation where the lightguide can include a second lightguide end (142) located at a distance from the axis of rotation where the second lightguide end is optically coupled to the optical transmitter. The apparatus can additionally include an optical receiver (135) coupled to the second housing at the axis of rotation where the optical receiver can also be optically coupled to the lightguide at the first lightguide end.