Executive Summary : | Optical fiber sensors have been a significant research area for decades, with various types developed for various applications such as molecular sensing, humidity sensing, pressure sensing, tilt sensing, liquid analyte sensing, salinity sensing, ultrasonic sensing, and magnetic field detection. These sensors use techniques like mode-locked lasers, long-period fiber gratings, Stimulated Brillouin scattering, photonic crystal fibers, Raman scattering, fiber Bragg gratings, and Fabry-Perot interferometers (FPI). Interferometer-based fiber optic sensors are highly valued due to their ease of operation, high sensitivity, high resolution, and multiplexing capabilities. Fabry-Perot interferometry-based sensors rely on changes in fringe visibility and cavity finesse to detect variations in the physical environment, while Mach-Zehnder interferometer (MZI) sensors have been used in various sensing applications such as refractive index sensing, strain sensing, and temperature sensing. Biosensing applications typically involve functionalizing the sensing region's surface with antibodies that bind specifically to the antigens being tested. Traditional biosensing methods, such as ELISA and radioimmunoassay, can be time-consuming, expensive, and require complex operations, labeling, and bulky instruments. Researchers have proposed various structures to enhance detection sensitivity, but these often suffer from poor mechanical stability and complex fabrication processes.
This work proposes a high precision, cost-effective hybrid interferometric optical fiber biosensor that combines the benefits of both Fabry-Perot interferometry (FPI) and Mach-Zehnder interferometry (MZI). The proposed sensor can identify and quantify a specific bio entity under test, crucial for minimizing disease outbreaks and providing timely guidance for regulatory agencies. |