scholarly journals Novel S-Bend Resonator Based on a Multi-Mode Waveguide with Mode Discrimination for a Refractive Index Sensor

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3600 ◽  
Author(s):  
Do-Hyun Kim ◽  
Su-Jin Jeon ◽  
Jae-Sang Lee ◽  
Seok-Ho Hong ◽  
Young-Wan Choi
Keyword(s):  
Refractive Index ◽  
Single Mode ◽  
Higher Order ◽  
Optical Resonators ◽  
Refractive Index Sensor ◽  
Bending Loss ◽  
Wide Line ◽  
Mode Discrimination ◽  
The Difference ◽  
Multi Mode

In this paper, a multi-mode waveguide-based optical resonator is proposed for an integrated optical refractive index sensor. Conventional optical resonators have been studied for single-mode waveguide-based resonators to enhance the performance, but mass production is limited owing to the high fabrication costs of nano-scale structures. To overcome this problem, we designed an S-bend resonator based on a micro-scale multi-mode waveguide. In general, multi-mode waveguides cannot be utilized as optical resonators, because of a performance degradation resulting from modal dispersion and an output transmission with multi-peaks. Therefore, we exploited the mode discrimination phenomenon using the bending loss, and the resulting S-bend resonator yielded an output transmission without multi-peaks. This phenomenon is utilized to remove higher-order modes efficiently using the difference in the effective refractive index between the higher-order and fundamental modes. As a result, the resonator achieved a Q-factor and sensitivity of 2.3 × 103 and 52 nm/RIU, respectively, using the variational finite-difference time-domain method. These results show that the multi-mode waveguide-based S-bend resonator with a wide line width can be utilized as a refractive index sensor.

A High Sensitivity Index Sensor Based on No-Core Fibers

2013 ◽  
Vol 284-287 ◽  
pp. 1986-1990
Author(s):  
Guei Ru Lin ◽  
Ming Yue Fu ◽  
Hao Jan Sheng ◽  
Hai Tao Sun ◽  
Wen Fung Liu
Keyword(s):  
Refractive Index ◽  
High Sensitivity ◽  
Single Mode ◽  
Wavelength Shift ◽  
Refractive Index Sensor ◽  
Sensitivity Index ◽  
Reflective Index ◽  
Index Measurement ◽  
Core Fiber ◽  
Multi Mode

A simple, small-size, compact and high-sensitivity refractive-index sensor composed of a short no-core fiber (NCF) about 20 mm in length sandwiched between two pieces of single-mode fibers is proposed in this paper. The index measurement is experimentally demonstrated with the sensitivity of 7792.85 nm/ RIU in the range from 1.440 to 1.454 and 227.14 nm/ RIU in the range from 1.300 to 1.430. This sensing mechanism is based on the induced multi-mode interfering wavelength shift in the no-core fiber when the reflective index of the fiber outside is changed.

scholarly journals Strain and Curvature Stability Enhanced SMF Introduction

2017 ◽  
Vol 6 (1) ◽  
pp. 63
Author(s):  
S. Makouei
Keyword(s):  
Refractive Index ◽  
Optical Fiber ◽  
Design Method ◽  
Single Mode ◽  
Effective Area ◽  
Refractive Index Profile ◽  
Curvature Radius ◽  
Geometrical Parameters ◽  
Small Curvature ◽  
Bending Loss

In this paper, the strain insensitive single mode optical fiber with low nonlinear effects and ultra low bending loss (BL), appropriate for small curvature radius installation, is presented. The suggested design method is based on the reverse engineering which evaluates the refractive index profile considering proper mode field diameter (MFD) value. Then, so as to attain the desired bending loss and strain response for the optical fiber, the optimization tool of the evolutionary genetic algorithm (GA) is employed to determine the optical and geometrical parameters of the structure. In the first designed fiber, the calculations for BL, MFD, effective area (Aeff), and effective refractive index (neff) sensitivity to strain in the well-known wavelength of 1.55 µm are 0.0018 dB per each turn of 5 mm curvature radius, 8.53 µm, 58 µm2, and 4.5 × 10-8 µɛ-1, respectively. Furthermore, the effect of placing raised outer cladding in the fiber structure is investigated which exhibits the MFD of 8.63 µm, 0.0093 dB BL for single turn of 5 mm radius, and 87 µm2 Aeff at 1.55 µm. In this case the strain sensitivity of 6.7 × 10-8 µɛ-1 is calculated for the neff. The mentioned effective area is magnificently large in the domain of bend insensitive fibers. In the meantime, the designed structures are insensitive to strain which is a crucial feature in applications with small curvature radius.

scholarly journals Single mode tapered fiber-optic interferometer based refractive index sensor and its application to protein sensing

2014 ◽  
Vol 22 (19) ◽  
pp. 22802 ◽  
Author(s):  
T. K Yadav ◽  
R. Narayanaswamy ◽  
M. H. Abu Bakar ◽  
Y. Mustapha Kamil ◽  
M. A. Mahdi
Keyword(s):  
Refractive Index ◽  
Fiber Optic ◽  
Single Mode ◽  
Refractive Index Sensor ◽  
Protein Sensing ◽  
Tapered Fiber ◽  
Fiber Optic Interferometer

scholarly journals Preparation and Characterization of Microsphere ZnO ALD Coating Dedicated for the Fiber-Optic Refractive Index Sensor

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 306 ◽  
Author(s):  
Paulina Listewnik ◽  
Marzena Hirsch ◽  
Przemysław Struk ◽  
Matthieu Weber ◽  
Mikhael Bechelany ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Fiber ◽  
Fiber Optic ◽  
Single Mode ◽  
Atomic Layer ◽  
Fiber Optic Sensor ◽  
Refractive Index Sensor ◽  
Layer Deposition ◽  
Fabry Perot

We report the fabrication of a novel fiber-optic sensor device, based on the use of a microsphere conformally coated with a thin layer of zinc oxide (ZnO) by atomic layer deposition (ALD), and its use as a refractive index sensor. The microsphere was prepared on the tip of a single-mode optical fiber, on which a conformal ZnO thin film of 200 nm was deposited using an ALD process based on diethyl zinc (DEZ) and water at 100 °C. The modified fiber-optic microsphere was examined using scanning electron microscopy and Raman spectroscopy. Theoretical modeling has been carried out to assess the structure performance, and the performed experimental measurements carried out confirmed the enhanced sensing abilities when the microsphere was coated with a ZnO layer. The fabricated refractive index sensor was operating in a reflective mode of a Fabry–Pérot configuration, using a low coherent measurement system. The application of the ALD ZnO coating enabled for a better measurement of the refractive index of samples in the range of the refractive index allowed by the optical fiber. The proof-of-concept results presented in this work open prospects for the sensing community and will promote the use of fiber-optic sensing technologies.

scholarly journals A Sensitivity-Enhanced Refractive Index Sensor Using a Single-Mode Thin-Core Fiber Incorporating an Abrupt Taper

Sensors ◽  
2012 ◽  
Vol 12 (4) ◽  
pp. 4697-4705 ◽  
Author(s):  
Jie Shi ◽  
Shilin Xiao ◽  
Lilin Yi ◽  
Meihua Bi
Keyword(s):  
Refractive Index ◽  
Single Mode ◽  
Refractive Index Sensor ◽  
Core Fiber
Sign in / Sign up

Export Citation Format

Share Document