Optical fiber-based sensing is uniquely qualified for a wide range of harsh environment applications due to the ability of optical fiber to withstand high temperature or chemically corrosive conditions. While off-the-shelf silica fiber is stable up to 800-900°C under a wide range of conditions, single crystal fiber offers a pathway to operation above 1000°C. Current single crystal fiber growth techniques are limited to producing multimode fiber, which limits interrogation approaches to primarily time-domain techniques. Raman-based distributed temperature sensing is one time-domain technique which has demonstrated significant utility for distributed temperature sensing in conjunction with multimode, single crystal fiber.