An optical ground wire (also known as an OPGW or, in the IEEE standard, an optical fiber composite overhead ground wire) is a type of cable that is used in overhead power lines. Such cable combines the functions of grounding and telecommunications. An OPGW cable contains a tubular structure with. OPGW cable, short for Optical Ground Wire or Optical Fiber Composite Overhead Ground Wire, represents a sophisticated engineering solution that integrates two critical functions into a single overhead cable.