A connector system is provided to connect a carriage that includes a rotatable drive member to a surgical instrument that includes a driven member, comprising. a mechanical interface that includes a drive transmission member configured to receive a rotational drive force provided by the drive member at the internal surface region and to provide a corresponding rotational drive force to the driven member at the external surface region; and a support to mount an end portion of an optical fiber to the mechanical interface with a center axis of the first end portion aligned with an axis of rotation of the drive transmission member.