Reliable temperature measurement of high-voltage transmission lines is critical to help meet the rising demand for electricity. Advanced optical fibers from Lightera integrated in Distributed Temperature Sensing on power lines help ensure optimal safety and performance in both medium- and long-distance systems. For Raman interrogation applications in spans of 15 kms, we offer graded-index multimode fibers for DTS measurements. These fibers are optimized for compatibility with traditional Raman-based DTS interrogators. The cable constructions can be used in applications with temperatures up to 125 ˚C. For interrogation spans up to 60 kms, our single-mode solution is recommended. This fiber optic solution is compatible with Brillouin detection systems. A single Brillouin peak profile is offered in a variety of products. Here too, the cable constructions can be used in applications with temperatures up to 125 ˚C.