Data transfer system incorporating optical fiber link module with internal electromagnetic shield

The invention provides an internal electromagnetic shield that prevents the radiation of electromagnetic emissions from electro-optical components in high speed data transfer systems. The present invention provides an internal shield with at least one aperture to allow the connector portion of an electro-optic component to pass through for connection to an optical fiber. By providing an internal shield, electromagnetic interference (EMI) is substantially reduced without interfering with the mechanical connection between an electro-optical component and an optical fiber. The internal shield typically is formed of a thin metallic sheet having apertures to receive the connector portion of electro-optical components. In a shield for an input/output device, which includes an optical signal generator and optical signal receiver, the shield may include two bores.