Standard silica-based optical fibers are currently being used in a wide variety of sensing applications where the operating temperatures do not exceed 500°C. In a number of applications where higher temperatures are encountered and harsh environments are unavoidable, it is imperative that both optical waveguides and optical waveguide coatings fabricated from materials other than silica be considered. Sapphire is one such candidate material that possesses reasonable optical propagation properties in both fiber and rod form, and can potentially perform without significant degradation under harsh conditions, including temperatures up to 2000°C.