Multiplexed fiber-optic Fabry-Pérot cavities for refractive index and temperature sensing fabricated using diamond-blade dicing

We report on multiplexing several Fabry-Pérot (FP) cavities in single-mode optical fibers for highprecision spatially resolved sensing of refractive indices (RI) of liquids. Resonators are fabricated by cutting small slots into fibers using a diamond-blade dicing saw and additional coating with thin Ta2O5 layers to increase cavity reflectance. Temperature compensation of RI measurements is achieved either by evaluating the reflection signals resulting from the solid core parts between different open-cavity sensor elements, or by using a thin Si inlay glued into one of the open cavities. The multiplexing performance and accuracy of the fabricated sensors with up to four open cavities were tested on sucrose solutions over a range of temperatures.

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An Easily Fabricated High Performance Fabry-Perot Optical Fiber Humidity Sensor Filled with Graphene Quantum Dots

Sensors ◽

10.3390/s21030806 ◽

2021 ◽

Vol 21 (3) ◽

pp. 806

Author(s):

Ning Wang ◽

Wenhao Tian ◽

Haosheng Zhang ◽

Xiaodan Yu ◽

Xiaolei Yin ◽

...

Keyword(s):

Quantum Dots ◽

Relative Humidity ◽

Optical Fiber ◽

Optical Fibers ◽

High Performance ◽

Humidity Sensor ◽

Graphene Quantum Dots ◽

High Sensitivity ◽

Single Mode ◽

Fabry Perot

An easily fabricated Fabry-Perot optical fiber humidity sensor with high performance was presented by filling Graphene Quantum Dots (GQDs) into the Fabry-Perot resonator, which consists of two common single mode optical fibers. The relative humidity sensing performance was experimentally investigated by an interference spectrum drift between 11 %RH to 85 %RH. 0.567 nm/%RH sensitivity and 0.99917 linear correlation were found in experiments that showed high sensitivity, good and wide-range linear responding. Meanwhile, its good responding repeatability was demonstrated by two circle tests with increasing and decreasing relative humidity. For investigating the measurement influence caused by a temperature jitter, the temperature responding was experimentally investigated, which showed its linear responding with 0.033 nm/°C sensitivity. The results demonstrate the humidity sensitivity is greatly higher than the temperature sensitivity. The wavelength shift influence is 0.0198 nm with 0.6 °C max temperature jitter in the experiment, which can be ignored in humidity experiments. The fast-dynamic responses at typical humidity were demonstrated in experiments, with 5.5 s responding time and 8.5 s recovering time. The sensors with different cavity lengths were also investigated for their humidity response. All sensors gave good linear responding and high sensitivity. In addition, the relation curve between cavity length and response sensitivity also had good linearity. The combination of GQDs and single mode optical fibers showed easy fabrication and good performance for an optical fiber relative humidity sensor.

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Spatially resolved measurement of chromatic dispersion and Brillouin shift along single-mode optical fibers

10.1117/12.566638 ◽

2004 ◽

Author(s):

Miguel Gonzalez Herraez ◽

Luc Thevenaz

Keyword(s):

Optical Fibers ◽

Chromatic Dispersion ◽

Single Mode ◽

Spatially Resolved

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Phase Sensitivity of Conventional Single-Mode, PANDA, and Holey Optical Fibers: A Comparison Study

10.21236/ada408460 ◽

2002 ◽

Author(s):

Wilson K. Chiu ◽

Jason M. Maguire ◽

Marilyn J. Berliner

Keyword(s):

Optical Fibers ◽

Single Mode ◽

Phase Sensitivity ◽

Comparison Study

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Design Considerations in Reduced-Diameter Single-Mode Optical Fibers

10.21236/ada633188 ◽

2002 ◽

Author(s):

Wilson K. Chiu ◽

Gregory H. Ames ◽

Marilyn J. Berliner

Keyword(s):

Optical Fibers ◽

Single Mode ◽

Design Considerations

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Sensing, Actuation, and Control of the SmartX Prototype Morphing Wing in the Wind Tunnel

Actuators ◽

10.3390/act10060107 ◽

2021 ◽

Vol 10 (6) ◽

pp. 107

Author(s):

Nakash Nazeer ◽

Xuerui Wang ◽

Roger M. Groves

Keyword(s):

Wind Tunnel ◽

Optical Fibers ◽

Fiber Optic ◽

Experimental Testing ◽

Single Mode ◽

Fiber Optic Sensor ◽

Sensor Data ◽

Random Errors ◽

Morphing Wing ◽

Actuator Dynamics

This paper presents a study on trailing edge deflection estimation for the SmartX camber morphing wing demonstrator. This demonstrator integrates the technologies of smart sensing, smart actuation and smart controls using a six module distributed morphing concept. The morphing sequence is brought about by two actuators present at both ends of each of the morphing modules. The deflection estimation is carried out by interrogating optical fibers that are bonded on to the wing’s inner surface. A novel application is demonstrated using this method that utilizes the least amount of sensors for load monitoring purposes. The fiber optic sensor data is used to measure the deflections of the modules in the wind tunnel using a multi-modal fiber optic sensing approach and is compared to the deflections estimated by the actuators. Each module is probed by single-mode optical fibers that contain just four grating sensors and consider both bending and torsional deformations. The fiber optic method in this work combines the principles of hybrid interferometry and FBG spectral sensing. The analysis involves an initial calibration procedure outside the wind tunnel followed by experimental testing in the wind tunnel. This method is shown to experimentally achieve an accuracy of 2.8 mm deflection with an error of 9%. The error sources, including actuator dynamics, random errors, and nonlinear mechanical backlash, are identified and discussed.

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Design and analysis of a fiber-optic sensing system for shape reconstruction of a minimally invasive surgical needle

Scientific Reports ◽

10.1038/s41598-021-88117-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Aizhan Issatayeva ◽

Aida Amantayeva ◽

Wilfried Blanc ◽

Daniele Tosi ◽

Carlo Molardi

Keyword(s):

Performance Analysis ◽

Minimally Invasive ◽

Optical Fibers ◽

Single Mode ◽

Spectral Shift ◽

Shape Reconstruction ◽

Minimally Invasive Surgical ◽

Working Principle ◽

Doped Fibers ◽

Distributed Measurement

AbstractThis paper presents the performance analysis of the system for real-time reconstruction of the shape of the rigid medical needle used for minimally invasive surgeries. The system is based on four optical fibers glued along the needle at 90 degrees from each other to measure distributed strain along the needle from four different sides. The distributed measurement is achieved by the interrogator which detects the light scattered from each section of the fiber connected to it and calculates the strain exposed to the fiber from the spectral shift of that backscattered light. This working principle has a limitation of discriminating only a single fiber because of the overlap of backscattering light from several fibers. In order to use four sensing fibers, the Scattering-Level Multiplexing (SLMux) methodology is applied. SLMux is based on fibers with different scattering levels: standard single-mode fibers (SMF) and MgO-nanoparticles doped fibers with a 35–40 dB higher scattering power. Doped fibers are used as sensing fibers and SMFs are used to spatially separate one sensing fiber from another by selecting appropriate lengths of SMFs. The system with four fibers allows obtaining two pairs of opposite fibers used to reconstruct the needle shape along two perpendicular axes. The performance analysis is conducted by moving the needle tip from 0 to 1 cm by 0.1 cm to four main directions (corresponding to the locations of fibers) and to four intermediate directions (between neighboring fibers). The system accuracy for small bending (0.1–0.5 cm) is 90$$\%$$ % and for large bending (0.6–1 cm) is approximately 92$$\%$$ % .

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Dispersion properties of single-mode optical fibers in telecommunication region: poly (methyl methacrylate) (PMMA) versus silica

Journal of Optical Communications ◽

10.1515/joc-2020-0172 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Hassan Pakarzadeh ◽

Seyed Mostafa Rezaei ◽

Mostafa Taghizadeh ◽

Forough Bozorgzadeh

Keyword(s):

Methyl Methacrylate ◽

Optical Fibers ◽

Spectral Range ◽

Structural Parameters ◽

Practical Importance ◽

Single Mode ◽

Dispersion Characteristics ◽

Poly Methyl Methacrylate ◽

Dispersion Wavelength ◽

Zero Dispersion Wavelength

AbstractIn this paper, the dispersion characteristics of two standard single-mode optical fibers (SMFs), fabricated with silica and poly (methyl methacrylate) (PMMA) are studied in telecommunication spectral regions. The effect of structural parameters, such as the radius of the fiber core and the relative core-cladding index difference, is numerically investigated. It is found that over whole spectral range, the PMMA-based SMF shows lower dispersion than the silica SMF. Also, the zero-dispersion wavelength (ZDW) of PMMA-based SMF is longer than that of silica fiber. The results may be of practical importance for the telecommunication applications.

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