A novel optical fiber sensor based on a balloon-shaped bent single-mode (BSBS) structure incorporating long-period grating (LPG) for simultaneous measurement of displacement and temperature is described experimentally demonstrated. The fabricated by splicing BSBS Mach-Zehnder interferometer (MZI) with (LPG). interference dip formed the sensitive to external variation, while that an LPG only depends temperature, displacement, and, therefore, can be unambiguously simultaneously measured this...

A novel relative humidity sensor based on a singlemode-side polished multimode-singlemode fibre structure coated with gelatin material is reported. The sensing principle and fabrication method of the proposed are presented. experimental demonstrated to provide optimum thickness coating layers in order achieve highest sensitivity 0.14 dB/%RH fast response time 1000 ms for given range. developed optic shows great potential many applications such as industrial production, food processing,...

A fibre-optic strain sensor based on a gourd-shaped joint multimode fibre (MMF) sandwiched between two single-mode fibres (SMFs) is described both theoretically and experimentally. The cladding layers of the MMFs are reshaped to form hemisphere using an electrical arc method spliced together, yielding required gourd shape. section forms Fabry-Perot cavity ends adjacent but non-contacting fibres' core. effectiveness interference interferometer (FPI) formed within inter-fibre greatly improved...

A high sensitivity optical fibre temperature sensor is demonstrated based on a balloon-shaped bent single-mode (BSBS) structure where the retains its original protective polymer coating.The BSBS can be simply realized by bending coated straight (SMF) into balloon shape using section of silica capillary tube.By adjusting radius section, modal interferometer between core mode and coating effectively implemented at suitable radius.Considering intrinsically thermo-optical coefficient (TOC)...

A relative humidity (RH) sensor based on a simple singlemode-side polished multimode-singlemode (SSPMS) fiber hybrid structure is investigated, which capable of working over relatively high-temperature range, at many RH sensors moisture sensitive material coatings cannot operate. The beam propagation method used to analyze the light transmission characteristics within side multimode (SPMMF) structure. Experimental results show that SPMMF surface roughness has significant influence sensor's...

A novel optical fiber displacement sensor based on composite interference established within a balloon-shaped bent multimode (BSBM) structure is described and experimentally demonstrated. The BSBM realized by bending straight single-mode-multimode-single-mode (SMS) into balloon shape using length of capillary tube to fix the structure. Owing bend in waveguide, original undistorted pattern changed, an extra Mach-Zehnder interferometer effectively introduced (MMF) section at suitable radius....

A novel, MMI-based all-fiber structure, which consists of two single-mode fibers and a multimode fiber polished on both sides, is described.The light propagation characteristics this as well its superior sensing performance, are analyzed theoretically by using the beam method (BPM).This structure demonstrates significant spectral response to changes surrounding refractive index (RI), measured results exhibit good agreement with predicted data.The average RI sensitivity high 151.29 nm/RIU...

Abstract In this paper, a theoretical and experimental investigation of the multimode interference induced self‐imaging phenomenon in singlemode‐multimode‐singlemode (SMS) fiber structure is described. The simulated transmission spectra based on guided modal propagation analysis beam method are presented compared with obtained results. temperature dependence position SMS also investigated. These investigations provide excellent opportunities for multiple future applications including...

This paper investigated the fabrication of a singlemode-multimode-singlemode fiber structure based on chalcogenide (As <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> S xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> and As xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> ) multimode sandwiched between two standard silica singlemode fibers using commercial fusion splicer. The...

Angle measurement based on heterodyne interferometer has been attracted much research interest and applied in various fields ranging from scientific to practical engineering. However, a systematic the typical angular not presented before. This paper mainly focused error analysis of its dynamic performance. The influence factors originating optical configuration, mechanical installation environmental fluctuations accuracy is analyzed. Furthermore, performance angle measuring angle, especially...

Primary angular vibration calibration devices based on laser interferometers play a crucial role in evaluating the dynamic performance of inertial sensing devices. Here, we propose sinusoidal phase-modulated angle interferometer (SPMAI) to realize measurements over frequency range 1–1000 Hz, which measurement retro-reflector (SMR) and phase generation carrier (PGC) demodulation algorithm are adopted track variation. A comprehensive theoretical analysis is presented reveal relationship...

Many researchers from scientific and industrial fields have devoted their efforts to the laser interferometer, aiming improve measurement accuracy extend practical applications. Here, we present a modified homodyne interferometer based on phase modulation for simultaneously measuring displacement angle. The active sawtooth wave enhances immunity of this environmental fluctuations power drift. Based polarized optic theory sinusoidal retro-reflector, Michelson-type configuration is designed...

The paper describes a multimode-interference-effect-based single-mode–multimode–single-mode (SMS) fiber optic sensing system for wide-range displacement monitoring on an Ilizarov orthopedic external fixation device. Displacement measurement is implemented as the uniform extension of spring, which connected to SMS optical sensor, allowing full characterization. structures are used together with macrobending-fiber-based interrogation measure temperature perturbation and hence eliminate its...

Abstract The laser technique based sensors and actuators can provide many superior properties as noncontact, high sensitivity, remote operation, reliable performance in contrast to other mechanical electrical techniques. In this paper, we design fabricate a high‐precision 360° receiver for leveling, especially agricultural construction field. is primarily composed of photoelectrical conversion module, signal processing display panel module. Based on the centroid method, detection error with...

We propose an all-fiber multimode interferometer based on a core-offset SMS fiber structure, and demonstrate that the lateral value has big impact interference re-imaging phenomenon within it.

A single-mode–multimode–single-mode (SMS) optical fiber-based displacement sensing system mounted on an Ilizarov transverse tibial bone transport device for microcirculation reconstruction is reported. Wide-range approximated as a uniform extension of spring that connected to SMS fiber structure acting the sensor and allowing full characterization. Transmission spectrum changes are measured, providing range 24 mm with sensitivity <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...