Development of hollow coaxial cable Fabry Perot Resonator for high temperature sensing applications

The thesis is comprised of two papers, the first paper presents the novel High-Quality Factor Coaxial Cable Fabry-Perot Resonator for sensing applications. The sensor is fabricated by creating two highly reflective mirrors in a coaxial cable. The temperature response of the sensor was tested, by monitoring the frequency shift of the reflection spectra as the temperature increased linearly from 35 °C to 80 °C in steps of 5 °C. The sensor exhibited high temperature sensitivity and good measurement resolution. A high Q factor of 133 was recorded. The second paper in the thesis presents a low cost, robust, homemade hollow coaxial cable Fabry-Perot resonator for high temperature sensing applications. In a hollow coaxial cable, the traditional dielectric polyethylene insulator is replaced by air. This sensor is also based upon the Fabry-Perot resonator, which is fabricated by making two highly reflective mirrors in the hollow coaxial cable. The temperature response of the sensor is tested, by monitoring the frequency shift of the reflection spectra as the temperature is increased from 100 °C to 600 °C and decreased back to 100 °C in steps of 50 °C. The proposed sensor exhibited good sensitivity, stability and repeatability. For demonstration, in this paper the hollow coaxial cable was fabricated using stainless steel, but it can also be fabricated with high temperature conductive materials like tungsten, nickel, cobalt alloys, conductive ceramics, which can operate in ultra-high temperatures (e.g., up to 1600 °C) --Abstract, page iv