Abstract
This manuscript experimentally validates a thin-film polymer and multimode fiber optic interaction-based low-cost optical fiber displacement sensor. The sensing setup is operated by deflecting a commercially Mylar Ⓡ polymer film using multimode optical fiber. The sensor exhibits a higher sensitivity of 24nm/<inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula> and resolution of 41.6nm. The sensor's analyses also demonstrate good polynomial approximation, with a maximal adjusted square of <inline-formula> <tex-math notation="LaTeX">\text {R}={0.9801} </tex-math></inline-formula>, and high stability, in which minimal power (0.4dB-Hour) and wavelength (< 2nm-Hour) variations are observed. Moreover, thermal experiments prove that the sensor has lower temperature traits (<inline-formula> <tex-math notation="LaTeX">0.05~\mu \text{m}/^{\circ }\text{C} </tex-math></inline-formula>), and this parameter can be distinguished considering the wavelength shifting direction. The simplicity of the scheme, as well as the cost of the elements involved, make this technique a reliable alternative to detect micro-displacements.