A Physics Department Faculty Member Publishes a Scientific Paper
Assistant Professor Dr. Safaa Mohammed Reda from the Physics Department published a scientific paper titled: “Modeling of a Multi-Layer Fiber-Optic Fabry-Perot Interferometer as a Sensing Element of Humidity, Pressure, and Temperature.”
The paper was published in the journal Proceedings of SPIE – The International Society for Optical Engineering, indexed in Scopus (Q4).
The research aimed to explore the concept of a fiber-optic sensing element that allows for the simultaneous measurement of humidity, pressure, and temperature, based on a multi-layer Fabry-Perot interferometer (FPI). The core element of this proposed instrument is a droplet-shaped air-filled cavity, produced using the catastrophic valve effect of single-mode fibers. The cavity opening is covered by a double-layered membrane. The first (inner) layer has an increased thermo-optical coefficient, while the second (outer) layer’s refractive index is sensitive to ambient humidity.
The research demonstrated that external pressure causes membrane deflection, resulting in a change in the length of the air-filled cavity. The work also discusses the material parameter requirements for the sensor, based on spectral modeling of the sensor structure under various ambient conditions, to achieve the desired measurement performance.
The study concluded that the proposed multilayer Fabry-Perrot interferometer, consisting of an air-filled cavity at the end of an optical fiber covered by a double-layered membrane, is capable of simultaneously measuring ambient pressure, humidity, and temperature. The sensor modeling results, based on the transport matrix method, show that the aforementioned environmental parameters can be determined using the sensor spectrum’s fast Fourier transform.
