Selectively Liquid-Infiltrated Microstructured Optical Fiber for Simultaneous Temperature and Force Measurement

A dual-parameter sensor based on a liquid-infiltrated microstructured optical fiber (MOF) is constructed by selective liquid infiltration of one particular cladding air hole in the MOF. The fundamental core mode could be simultaneously coupled to several higher order modes of the adjacent liquid rod waveguide when the phase-matching condition is satisfied, resulting in the emergence of multiple resonance peaks with different sensing characteristics. Our proposed liquid-infiltrated MOF sensor has several advantages, such as high sensitivity and a large measurement range. Moreover, it is able to resolve the temperature-force cross-sensitivity issue that is commonly encountered in most practically deployed sensing components.