Anomalous Enhancement of Volume and Surface Refractive Index Sensitivity of Fiber Bragg Grating Sensors with Deposition of Gold Nanoparticles

The low refractive index sensing principle of the fiber Bragg grating (FBG) was analyzed theoretically, the temperature compensation scheme corresponding to the theoretical model was established. A single-end etched FBG was designed and fabricated for simultaneous measurement of temperature and refractive index. The experimental results demonstrated that the Bragg wavelength shift exhibits a nonlinear behavior with the temperature and yeast refractive index changes. The temperature change to the influence of the sensor was eliminated by numerical analysis, and then the relationship between the Bragg wavelength shift and the yeast refractive index is linear, the sensor yeast refractive index sensitivity of 5.42nm/riu was obtained.

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Wavelet-Based Demodulation of Multimode Etched Fiber Bragg Grating Refractive Index Sensor

Sensors ◽

10.3390/s19010039 ◽

2018 ◽

Vol 19 (1) ◽

pp. 39 ◽

Cited By ~ 3

Author(s):

Takhmina Ayupova ◽

Marzhan Sypabekova ◽

Carlo Molardi ◽

Aliya Bekmurzayeva ◽

Madina Shaimerdenova ◽

...

Keyword(s):

Refractive Index ◽

Spectral Density ◽

Fiber Bragg Grating ◽

Bragg Grating ◽

Wavelength Shift ◽

Refractive Index Sensor ◽

Refractive Index Sensitivity ◽

Index Sensitivity ◽

Fiber Thickness ◽

Refractive Index Detection

Etched fiber Bragg grating (EFBG)-based sensors are used as evanescent field sensors for refractive index detection. When the fiber thickness is thin and the refractive index sensitivity increases, the number of propagating modes increases, resulting in a spectral enlargement that complicates the interrogation of the sensor. In this work, we present a method to analyze the spectrum of a multimode etched fiber Bragg grating (MMEFBG) in the wavelet domain, which analyzes the amount of spectral density independently from the peak reflectivity value. The proposed interrogation method permits defining the integral of the spectral density as a novel and unconventional estimator. With respect to the conventional estimators based on wavelength shift, this estimator can better exploit the larger amount of information given by the spectral enlargement typical of multimode behavior. Results were obtained by etching an MMEFBG in hydrofluoric acid and using water/sucrose mixtures to evaluate the refractive index sensitivity, validating the interrogation method.

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Refractive Index Sensing Based on a Fiber Bragg Grating with Micro-Holes

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.495.194 ◽

2011 ◽

Vol 495 ◽

pp. 194-197

Author(s):

Min Wei Yang ◽

D. N. Wang ◽

C. R. Liao

Keyword(s):

Refractive Index ◽

Fiber Bragg Grating ◽

Intensity Variation ◽

Bragg Grating ◽

Wavelength Shift ◽

Refractive Index Sensor ◽

Refractive Index Sensitivity ◽

Femtosecond Laser Micromachining ◽

Micro Holes ◽

Index Sensitivity

A refractive index sensor based on single fiber Bragg grating with multiple micro-holes is proposed. The micro-holes are drilled by use of femtosecond laser micromachining. The key feature of the sensor is that a simultaneous and independent refractive index and temperature sensing measurement can be implemented by simply detecting the grating resonant wavelength shift and its intensity variation, respectively. The refractive index sensitivity obtained is 29.50 dB/RIU (refractive index unit), within the refractive index range between 1.30 and 1.45.

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Refractive index sensitivity of fiber Bragg grating inscribed in a multimode fiber

2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC) ◽

10.1109/imoc.2015.7369180 ◽

2015 ◽

Cited By ~ 1

Author(s):

Jean Filipe Kuhne ◽

Valmir de Oliveira ◽

Hypolito Jose Kalinowski ◽

Ricardo Canute Kamikawachi

Keyword(s):

Refractive Index ◽

Fiber Bragg Grating ◽

Bragg Grating ◽

Multimode Fiber ◽

Refractive Index Sensitivity ◽

Index Sensitivity

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Ambiguous Refractive Index Sensitivity of Fano Resonance on an Array of Gold Nanoparticles

Plasmonics ◽

10.1007/s11468-013-9641-8 ◽

2013 ◽

Vol 9 (4) ◽

pp. 729-735 ◽

Cited By ~ 7

Author(s):

Barbora Špačková ◽

Petra Lebrušková ◽

Hana Šípová ◽

Pavel Kwiecien ◽

Ivan Richter ◽

...

Keyword(s):

Gold Nanoparticles ◽

Refractive Index ◽

Fano Resonance ◽

Refractive Index Sensitivity ◽

Index Sensitivity

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Optimizing the Refractive Index Sensitivity of Plasmonically Coupled Gold Nanoparticles

Plasmonics ◽

10.1007/s11468-013-9659-y ◽

2013 ◽

Vol 9 (4) ◽

pp. 773-780 ◽

Cited By ~ 29

Author(s):

Erik Martinsson ◽

Borja Sepulveda ◽

Peng Chen ◽

Anders Elfwing ◽

Bo Liedberg ◽

...

Keyword(s):

Gold Nanoparticles ◽

Refractive Index ◽

Refractive Index Sensitivity ◽

Index Sensitivity

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Shallow-Tapered Chirped Fiber Bragg Grating Sensors for Dual Refractive Index and Temperature Sensing

Sensors ◽

10.3390/s21113635 ◽

2021 ◽

Vol 21 (11) ◽

pp. 3635

Author(s):

Takhmina Ayupova ◽

Madina Shaimerdenova ◽

Daniele Tosi

Keyword(s):

Refractive Index ◽

Spectral Analysis ◽

Fiber Bragg Grating ◽

Thermal Characteristics ◽

Temperature Sensing ◽

Bragg Grating ◽

Fiber Bragg Grating Sensors ◽

Thermal Changes ◽

Chirped Fiber Bragg Grating

In this work, we present a gold-coated shallow-tapered chirped fiber Bragg grating (stCFBG) for dual refractive index (RI) and temperature sensing. The stCFBG has been fabricated on a 15-mm long chirped FBG, by tapering a 7.29-mm region with a waist of 39 μm. The spectral analysis shows two distinct regions: a pre-taper region, in which the stCFBG is RI-independent and can be used to detect thermal changes, and a post-taper region, in which the reflectivity increases significantly when the RI increments. We estimate the RI and thermal sensitivities as 382.83 dB/RIU and 9.893 pm/°C, respectively. The cross-talk values are low (−1.54 × 10−3 dB/°C and 568.1 pm/RIU), which allows an almost ideal separation between RI and thermal characteristics. The stCFBG is a compact probe, suitable for long-term and temperature-compensated biosensing and detection of chemical analytes.

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