An optical connector system for reversible optical connection between two optical fibers (102, 104) with their end parts inside respective ferrules. A receptacle arrangement has a receiving body (105) for receiving at least one of the ferrules (103). An optical element (106) of the receptacle arrangement serves to provide optical connection between the two optical fibers in a connected state of the optical connector system, and at the same time, the optical element (106) serves as a sterility barrier between the two optical fibers. The optical element (106) can be an optical waveguide, e.g. a piece of optical fiber similar to the two optical fibers (102, 104), and arranged within the receiving body (105). Alternatively, the optical element may be a thin flexible membrane (207, 307) which is optically transparent. As a further alternative, the optical element may be a sterilizing fluid (409) arranged in side a container that can be punctured upon insertion of one of the ferrules (401, 403) into the container (408), to allow an optical fiber end to be sterilized by the fluid (409) prior to entering into the connected state. In a further embodiment, an optical lens (312) is used to project light from one fiber end through a membrane (307) to the opposite fiber end.