Bend-Direction and Rotation Plastic Optical Fiber Sensor

Abstract

A plastic filament of poly (methyl methacrylate) (PMMA) was fabricated by extrusion. The mode confinement was simulated using numerical software. The idea is to study how the light intensity changes inside the plastic optical fiber (POF) when a bending in multiple directions is applied. The results obtained from the simulation were compared to the experimental observations. The non-circular shape of the POF allows sensing a rotation applied as well. The angle of rotation was obtained processing two images of the end facet of the fiber (one with the fiber in a reference position and one with the rotated fiber), using an intensity-based automatic image registration. The accuracy in the rotation calculation was of 0.01°.

Optical Fibre-Based Sensors—An Assessment of Current Innovations

“…Nano displacement was also detected utilizing a double-core fibre and an interferometric method. A three-lobe PMMA fibre core without cladding was used to create a non-circular optical fibre [ 139 ]. A specially designed extrusion die was used to create the three-lobe form after the filament was directly extruded from plastic pellets.…”

“…The lowest order modes in both the straight and bent fibres’ light fields were calculated using mode simulations. The lowest-order fibre mode’s simulated light field intensity is shown in Figure 9 c for the straight fibre [ 139 ].…”

An Overview on Methods for Producing Side-Emitting Polymer Optical Fibers

“…The bending losses of POF were investigated simulatively and experimentally in numerous studies in the past [40,42,46,[92][93][94][95][96]. For POF sensing, bending losses can be used as a feature, e.g., when it comes to measuring displacement [97], deformation [98], strain [99], pressure [100], weight [101], humidity [102], refractive index [95], breathing rate [103] or bending itself [104], among others, or to increase the penetration depth of evanescent waves [105] in other sensing applications.…”

Treatment of Mode Coupling in Step-Index Multimode Microstructured Polymer Optical Fibers by the Langevin Equation

“…POFs are good candidates for short-range transmission systems such as automotive and home network connections [ 2 , 3 ]. Moreover, due to their advantages such as a large negative thermo-optic coefficient, high bending flexibility, and large elastic strain limits, POFs are promising for sensing applications [ 4 , 5 , 6 , 7 , 8 , 9 ]. A microstructured optical fiber or photonic crystal fiber (PCF) was first demonstrated in 1996 with silica material [ 10 ], which can realize a wide variety of properties by different microstructures with a solid core and a hollow core [ 11 , 12 ].…”