Generally speaking, a variety of reinforcing materials are used for the reinforcing core of optical cables, including stainless steel wire and FRP.

The stainless steel wires used in optical cables and optical fiber sensors are mainly phosphated steel wires and galvanized steel wires. Of course, these two materials can withstand general high temperature, but the optical cables with these two materials are often not high temperature optical cables, and most of them are buried optical cables.

FRP is also commonly used as a reinforcing core in optical cables. FRP is mainly composed of glass fiber and polymer glue. Glass fiber, but polymer glue is not. Therefore, FRP materials are generally not, but can withstand medium and low temperatures of about 150 degrees Celsius.