{HEAD ~ a receiver module} disposed within {TAIL ~ the receiver module housing}, the receiver module having an optical to electrical converter for converting optical signals into electrical signals, wherein at least a portion of the optical signal propagating along the tube toward the second end of the tube passes out of the second end of the tube and is optically coupled onto the OEC 
{ HEAD ~ a receiver module } disposed within { TAIL ~ the receiver module housing } , the receiver module having an optical to electrical converter for converting optical signals into electrical signals , wherein at least a portion of the optical signal propagating along the tube toward the second end of the tube passes out of the second end of the tube and is optically coupled onto the OEC
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