Fiber optic temperature sensors offer wide dynamic range, immunity to electromagnetic interference and high sensitivity. They are typically used for measuring temperatures in applications such as plasma deposition. A sapphire-fiber thermometer with a temperature range from 20 to 1800 oC has been developed by physicists at Zhejiang University in Hangzhou, China. It combines radiance detection and fluorescence lifetime schemes into one system. Preliminary testing shows that the thermometer is suitable for practical applications requiring long-term stability and high-temperature resolution. The group's report appears in the March 1 issue of Applied Optics.