Semitransparent properties of an intrinsic silicon wafer and its application to an optical fiber temperature sensor

We have developed a silicon wafer embedded optical fiber temperature sensor which makes use of temperature dependent semitransparent properties of the wafer. We have proposed the two methods of temperature measurement: one is based on the absorption edge wavelength shift due to bandgap energy variation and the other utilizes the transmittance, or the reflectance variation due to free-carrier absorption with temperature. The temperature measurement is possible between −196 to 650 degrees Celsius. The sensor is particularly applicable in hostile and harsh environments filled with electric noise like plasma processes, inflammable gases and corrosive media.