EMI reduction for optical subassembly

An optoelectronic transmitter module for transmitting optical data signals from a host device housed within a grounded chassis, said module providing a reduced effective aperture through said chassis, said module comprising:

• electronic circuitry configured to convert digital electrical signals to optical signals;
• a plastic housing having an electrically conductive surface enclosing said electronic circuitry, said plastic housing having a first end adapted to receive a fiber optic connector, said first end further adapted to engage said chassis and be electrically connected thereto to form a conductive barrier at said first end of the plastic housing;
• and
• an electrically conductive transmitting optical subassembly disposed within said plastic housing having an electrically conductive surface forming a continuous conductive barrier therewith, said transmitting optical subassembly having first and second ends with a narrow passage therein providing communication between said first end including an optical package and said second end configured to receive a fiber optic connector ferrules.

An optoelectronic module having a reduced emissions aperture comprising:

• a plastic module housing having an electrically conductive surface electrically connected to a case ground potential of a host device and having an end comprising a fiber optic connector receptacle;
• a transmitting optical subassembly (TOSA) including an electrically conductive TOSA housing mounted adjacent the receptacle end of the plastic module housing, the plastic module housing and the electrically conductive TOSA housing including overlapping mating surfaces such that said electrically conductive surface of the plastic module housing and said electrically conductive TOSA housing form a continuous conductive barrier across said receptacle end, said electrically conductive TOSA housing defining a bore for receiving a fiber optic connector ferrule, an optics cavity, and a narrow passage between said bore and said cavity;
• an optical package mounted within said optics cavity, said optical package including a conductive outer covering engaging the electrically conductive TOSA housing such that said electrically conductive surface of the plastic module housing, said electrically conductive TOSA housing and said optical package outer covering are maintained at the case ground potential of said host device;
• and
• a signal ground pin electrically isolated from the optical package outer covering, and extending therethrough to supply a signal ground potential to an optical transmitting device housed within said optical package, said signal ground potential being distinct from said host device case ground potential.