Design and analyses of a periodic dielectric Bragg grating waveguide temperatures reported in this work. The sensor is capable to measure temperatures ranging from room temperature to over 1200° C. By using this sensor combined with a wavelength shifting detector and radiation detection schemes, a wide range thermometer can be built. Temperature can be measured in two steps using our thermal sensor. First step is to detect the wavelength shifting by an optical spectrum analyzer (OSA). The wavelength shifting could be converted to the change of environment temperature. This method is appropriate for the temperatures ranging from 20° C to 600° C. Another step is to detect the power of the probe radiation for the temperature range of over 600° C to the melting point of the probes. This sensor has potential applications in many areas particularly in aerospace industries..