There is provided a feedback-controlled self-heat-monitoring fiber, including an insulator having a fiber length with at least one metal-semiconductor-metal thermal sensing element along the fiber length and disposed at a position in a cross section of the fiber for sensing changes in fiber temperature. An electronic circuit is connected to the thermal sensing element for indicating changes in fiber temperature. A controller is connected for controlling optical transmission through an optical transmission element, that is disposed along the fiber length, in response to indications of changes in fiber temperature.