Ultra-Compact Full-Angle-Range Direction-Distinguishable Tilt Sensor Based on Fiber in-Line Polymer Microcavity

We propose an ultra-compact full-angle-range direction-distinguishable tilt sensor based on a polymer column working as a Fabry–Perot (FP) microcavity fixed between two sections of single-mode fibers (SMFs). The directional tilt angle from −90 deg to +90 deg can be demodulated by monitoring the wavelength shift of interference fringe, based on the deformation of the polymer column under the effect of the gravity force. The sensitivity of the sensor can be adjusted by changing the shape and size of the polymer column that is fabricated by the single beam illumination with high efficiency and low cost. The sensor can satisfy the engineering requirements owing to its small size, flexible structure, cost-effective performance, large measurement range, and direction-distinguishable ability.