Fiberguide Industries Inc. offers a full line of standard optical fibers with polyimide coating. Providing optimal performance of fiber optics in extreme thermal conditions, the coating accommodates oil and gas, aerospace, sensors, defense, and medical and security applications requiring high temperature resistance. It withstands operating temperatures of up to 400 °C (300 °C continuous), while conventional coatings such as acrylate, nylon and Tefzel begin to deteriorate between 100 and 250 °C. Polyimide-coated fiber is available in step-index, multimode fibers with cores from 50 to 600 µm, 6.25-/125-µm and 50-/125-µm graded index, and in 4.8-/125-µm and 9.2-/125-µm graded index single-mode fibers. According to the company, it offers high-performance optical and mechanical specifications with tight dimension tolerances to produce good uniformity.