scholarly journals Hybrid Grating in Reduced-Diameter Fiber for Temperature-Calibrated High-Sensitivity Refractive Index Sensing

2019 ◽  
Vol 9 (9) ◽  
pp. 1923
Author(s):  
Biqiang Jiang ◽  
Zhen Hao ◽  
Dingyi Feng ◽  
Kaiming Zhou ◽  
Lin Zhang ◽  
...  
Keyword(s):  
Refractive Index ◽  
Simultaneous Measurement ◽  
Surrounding Medium ◽  
High Sensitivity ◽  
Fiber Grating ◽  
Bragg Resonance ◽  
Core Mode ◽  
Promising Alternative ◽  
Sensing Applications ◽  
Highly Sensitive

We propose and experimentally demonstrate a hybrid grating, in which an excessively tilted fiber grating (Ex-TFG) and a fiber Bragg grating (FBG) were co-inscribed in a reduced-diameter fiber (RDF). The hybrid grating showed strong resonances due to coupling among core mode and a set of polarization-dependent cladding modes. This coupling showed enhanced evanescent fields by the reduced cladding size, thus allowing stronger interaction with the surrounding medium. Moreover, the FBG’s Bragg resonance confined by the thick cladding was exempt from the change of the surrounding medium’s refractive index (RI), and then the FBG can work as a temperature compensator. As a result, the Ex-TFG in RDF promised a highly sensitive RI measurement, with a sensitivity up to ~1224 nm/RIU near the RI of 1.38. Through simultaneous measurement of temperature and RI, the temperature dependence of water’s RI is then determined. Therefore, the proposed hybrid grating with a spectrum of multi-peaks embedded with a sharp Bragg resonance is a promising alternative for the simultaneous measurement of multi-parameters for many RI-based sensing applications.

Highly Sensitive THz Refractive Index Sensor Based on Folded Split-Ring Metamaterial Graphene Resonators

2021 ◽  
Author(s):  
Mohammad-Reza Nickpay ◽  
Mohammad Danaie ◽  
Ali Shahzadi
Keyword(s):  
Refractive Index ◽  
Biomedical Application ◽  
High Sensitivity ◽  
Peak Frequency ◽  
Refractive Index Sensor ◽  
Split Ring ◽  
Perfect Absorption ◽  
Sensing Applications ◽  
Highly Sensitive ◽  
Dc Bias

Abstract A highly sensitive absorption-based sensor based on folded split-ring metamaterial graphene resonators (FSRMGRs) is designed, and its biomedical application in terahertz (THz) spectrum is investigated. The sensor has a nearly perfect absorption with a spectral absorption coefficient of 99.75% at 4 THz, with a high Q-factor (average) of 13.76. The resonance peak frequency is sensitive to the refractive index (RI) of the test medium (analyte) and a fairly high sensitivity of 851 GHz/RIU has been obtained. The specifications of the sensor can be tuned by an external DC-bias voltage applied to the graphene layer. According to the obtained results, the developed absorber appears to be a good candidate bio-sensing applications.

scholarly journals Reusable TiN Substrate for Surface Plasmon Resonance Heterodyne Phase Interrogation Sensor

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1325 ◽  
Author(s):  
Ru-Jing Sun ◽  
Hung Ji Huang ◽  
Chien-Nan Hsiao ◽  
Yu-Wei Lin ◽  
Bo-Huei Liao ◽  
...  
Keyword(s):  
Refractive Index ◽  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
High Sensitivity ◽  
Nanorod Array ◽  
Glass Substrates ◽  
Sensing Applications ◽  
Bulk Charge ◽  
Phase Interrogation

A TiN-based substrate with high reusability presented high-sensitivity refractive index measurements in a home-built surface plasmon resonance (SPR) heterodyne phase interrogation system. TiN layers with and without additional inclined-deposited TiN (i-TiN) layers on glass substrates reached high bulk charge carrier densities of 1.28 × 1022 and 1.91 × 1022 cm−3, respectively. The additional 1.4 nm i-TiN layer of the nanorod array presented a detection limit of 6.1 × 10−7 RIU and was higher than that of the 46 nm TiN layer at 1.2 × 10−6 RIU when measuring the refractive index of a glucose solution. Furthermore, the long-term durability of the TiN-based substrate demonstrated by multiple processing experiments presented a high potential for various practical sensing applications.

Strain, torsion and refractive index sensors based on helical long period fibre grating inscribed in small-core fibre for structural condition monitoring

2021 ◽  
Vol 24 (6) ◽  
pp. 1248-1255
Author(s):  
Cailing Fu ◽  
Yi-Qing Ni ◽  
Tong Sun ◽  
Yiping Wang ◽  
Siqi Ding ◽  
...  
Keyword(s):  
Refractive Index ◽  
High Sensitivity ◽  
Single Mode ◽  
Structural Condition ◽  
Core Diameter ◽  
Small Core ◽  
Long Period ◽  
Sensing Applications ◽  
Core Fibre ◽  
Refractive Index Sensors

This study is intended to develop long period fibre grating sensors for potential applications in environmental and durability monitoring of coastal structures. High-quality helical long period fibre gratings (HLPFGs) are inscribed in different types of small-core single mode fibre (SMF) by use of hydrogen-oxygen flame heating technique. A detailed investigation of the effect of core diameter on their transmission spectrum and optimum length of the HLPFG has been pursued. A longer length is required to achieve the same coupling attenuation in a smaller-core SMF than that of a larger-core fibre. The strain, torsion and refractive index (RI) properties of the HLPFG is investigated experimentally to develop a high-sensitivity sensor. The experimental results show that the strain sensitivity could be enhanced by means of employing a larger-core diameter SMF. Moreover, the HLFPGs are also sensitive to the torsion and external RI. Hence, such HLFPGs have great potential for sensing applications.

Few-mode fiber-embedded long-period fiber grating for simultaneous measurement of refractive index and temperature

2020 ◽  
Vol 59 (29) ◽  
pp. 9248
Author(s):  
Shuo Zhang ◽  
Xiang Li ◽  
Huiwen Niu ◽  
Qi Yan ◽  
Cuiting Sun ◽  
...  
Keyword(s):  
Refractive Index ◽  
Simultaneous Measurement ◽  
Fiber Grating ◽  
Long Period Fiber Grating ◽  
Long Period ◽  
Period Fiber Grating

scholarly journals High Sensitivity Terahertz Biosensor Based on Mode Coupling of a Graphene/Bragg Reflector Hybrid Structure

Biosensors ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 377
Author(s):  
Yamei Liu ◽  
Qiwen Zheng ◽  
Hongxia Yuan ◽  
Shenping Wang ◽  
Keqiang Yin ◽  
...  
Keyword(s):  
Refractive Index ◽  
Mode Coupling ◽  
Defect Mode ◽  
High Sensitivity ◽  
Hybrid Structure ◽  
Transmission Peak ◽  
Bragg Reflector ◽  
Highly Sensitive ◽  
Specific Parameter ◽  
Resonance Transmission

In this work, a high-sensitivity terahertz (THz) biosensor is achieved by using a graphene/Bragg reflector hybrid structure. This high-sensitivity THz biosensor is developed from the sharp Fano resonance transmission peak created by coupling the graphene Tamm plasmons (GTPs) mode to a defect mode. It is found that the proposed THz biosensor is highly sensitive to the Fermi energy of graphene, as well as the thickness and refractive index of the sensing medium. Through specific parameter settings, the composite structure can achieve both a liquid biosensor and a gas biosensor. For the liquid biosensor, the maximum sensitivity of >1000°/RIU is obtained by selecting appropriate parameters. We believe the proposed layered hybrid structure has the potential to fabricate graphene-based high-sensitivity biosensors.

scholarly journals Highly compact refractive index sensor based on stripe waveguides for lab-on-a-chip sensing applications

2016 ◽  
Vol 7 ◽  
pp. 751-757 ◽  
Author(s):  
Chamanei Perera ◽  
Kristy Vernon ◽  
Elliot Cheng ◽  
Juna Sathian ◽  
Esa Jaatinen ◽  
...  
Keyword(s):  
Refractive Index ◽  
Linear Response ◽  
Lab On A Chip ◽  
Refractive Index Sensor ◽  
Label Free ◽  
Output Intensity ◽  
Sensing Applications ◽  
Index Analysis ◽  
Highly Sensitive ◽  
Index Unit

In this paper we report the design and experimental realisation of a novel refractive index sensor based on coupling between three nanoscale stripe waveguides. The sensor is highly compact and designed to operate at a single wavelength. We demonstrate that the sensor exhibits linear response with a resolution of 6 × 10−4 RIU (refractive index unit) for a change in relative output intensity of 1%. Authors expect that the outcome of this paper will prove beneficial in highly compact, label-free and highly sensitive refractive index analysis.

scholarly journals A Highly Sensitive Refractive Index Sensor Based on a V-Shaped Photonic Crystal Fiber with a High Refractive Index Range

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3782
Author(s):  
Xin Yan ◽  
Rao Fu ◽  
Tonglei Cheng ◽  
Shuguang Li
Keyword(s):  
Refractive Index ◽  
Photonic Crystal ◽  
Photonic Crystal Fiber ◽  
High Refractive Index ◽  
Refractive Index Sensor ◽  
Chemical Production ◽  
Refractive Index Sensitivity ◽  
Crystal Fiber ◽  
Sensing Applications ◽  
Highly Sensitive

This paper proposes a highly sensitive surface plasmon resonance (SPR) refractive index sensor based on the photonic crystal fiber (PCF). The optical properties of the PCF are investigated by modulating the refractive index of a liquid analyte. The finite element method (FEM) is used to calculate and analyze the PCF structure. After optimization, the fiber can achieve high linearity of 0.9931 and an average refractive index sensitivity of up to 14,771.4 nm/RIU over a refractive index range from 1.47 to 1.52, with the maximum wavelength sensitivity of 18,000.5 nm/RIU. The proposed structure can be used in various sensing applications, including biological monitoring, environmental monitoring, and chemical production with the modification and analysis of the proposed structure.

scholarly journals A Compact Double-Folded Substrate Integrated Waveguide Re-Entrant Cavity for Highly Sensitive Humidity Sensing

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3308 ◽  
Author(s):  
Zhihua Wei ◽  
Jie Huang ◽  
Jing Li ◽  
Junshan Li ◽  
Xuyang Liu ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
High Sensitivity ◽  
Substrate Integrated Waveguide ◽  
Humidity Sensing ◽  
Food Industries ◽  
High Q ◽  
Sensing Applications ◽  
Compact Size ◽  
Highly Sensitive ◽  
Humidity Chamber

In this study, an ultra-compact humidity sensor based on a double-folded substrate integrated waveguide (SIW) re-entrant cavity was proposed and analyzed. By folding a circular re-entrant cavity twice along its two orthogonally symmetric planes, the designed structure achieved a remarkable size reduction (up to 85.9%) in comparison with a conventional TM010-mode circular SIW cavity. The operating principle of the humidity sensor is based on the resonant method, in other words, it utilizes the resonant properties of the sensor as signatures to detect the humidity condition of the ambient environment. To this end, a mathematical model quantitatively relating the resonant frequency of the sensor and the relative humidity (RH) level was established according to the cavity perturbation theory. The sensing performance of the sensor was experimentally validated in a RH range of 30%–80% by using a humidity chamber. The measured absolute sensitivity of the sensor was calculated to be 135.6 kHz/%RH, and the corresponding normalized sensitivity was 0.00627%/%RH. It was demonstrated that our proposed sensor not only has the merits of compact size and high sensitivity, but also benefits from a high Q-factor and ease of fabrication and integration. These advantages make it an excellent candidate for humidity sensing applications in various fields such as the agricultural, pharmaceutical, and food industries.

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