Influence of polymer solution parameters on optical fiber Fabry-Perot polymer cavities

Abstract

Abstract Optical fiber polymer-based Fabry-Perot sensors are commonly utilized to detect and measure a wide range of physical and chemical properties. By dipping the cleaved end of a single mode fiber into the polymer solution, a cavity is formed at the end facet of the fiber, as the solution effectively bonds to the fiber surface. The cavity serves as a sensing structure for the interaction with the analyte, ultimately determining the sensor’s sensitivity. Maintaining consistent thickness of the FP cavities is of utmost importance for the coating mechanism, as it directly impacts the sensitivity of the FP sensor. The main aim of this study is to assess and establish a technique that can effectively generate a cavity at the end facet of a fiber. A simulation study is conducted to examine the influence of variations in polymer solution characteristics on the cavity fabrication. Our experimental work involved creating polymer cavities on varying the polymer viscosity on the end facet of optical fibers. Furthermore, the suitability of this proposed approach has been assessed on a range of polymers, examining the fluctuations in the free spectral range of the fabricated FP cavities. The findings of this research highlight the possibility of achieving a repeatable coating on the end facet of fiber, irrespective of the polymer used.