Optical Waveguides with Compound Multiperiodic Grating Nanostructures for Refractive Index Sensing

The spectral characteristics and refractive index sensitivity of compound multiperiodic grating waveguides are investigated in theory and experiment. Compound gratings are formed by superposition of two or more monoperiodic gratings. Compared to monoperiodic photonic crystal waveguides, compound grating waveguides offer more degrees of design freedom by choice of component grating periods and duty cycles. Refractive index sensing is achieved by evaluating the wavelength or intensity of guided mode resonances in the reflection spectrum. We designed, fabricated, and characterized 24 different compound multiperiodic nanostructured waveguides for refractive index sensing. Simulations are carried out with the Rigorous Coupled Wave Algorithm (RCWA). The resulting spectra, resonance sensitivities, and quality factors are compared to monoperiodic as well as to three selected aperiodic nanostructures (Rudin-Shapiro, Fibonacci, and Thue-Morse). The refractive index sensitivity of the TE resonances is similar for all types of investigated nanostructures. For the TM resonances the compound multiperiodic nanostructures exhibit higher sensitivity values compared to the monoperiodic nanostructure and similar values as the aperiodic nanostructures. No significant influence of the compound grating duty cycles on the sensitivity is observed.

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Refractive index sensing with Fano resonances in silicon oligomers

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2016.0070 ◽

2017 ◽

Vol 375 (2090) ◽

pp. 20160070 ◽

Cited By ~ 11

Author(s):

Katie E. Chong ◽

Henry W. Orton ◽

Isabelle Staude ◽

Manuel Decker ◽

Andrey E. Miroshnichenko ◽

...

Keyword(s):

Refractive Index ◽

Figure Of Merit ◽

Spectral Features ◽

Fano Resonances ◽

Refractive Index Sensitivity ◽

New Horizons ◽

Refractive Index Sensing ◽

Index Sensitivity

We demonstrate experimentally refractive index sensing with localized Fano resonances in silicon oligomers, consisting of six disks surrounding a central one of slightly different diameter. Owing to the low absorption and narrow Fano-resonant spectral features appearing as a result of the interference of the modes of the outer and the central disks, we demonstrate refractive index sensitivity of more than 150 nm RIU −1 with a figure of merit of 3.8. This article is part of the themed issue ‘New horizons for nanophotonics’.

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Improved Refractive Index Sensitivity Utilizing Long-Period Gratings with Periodic Corrugations on Cladding

Journal of Sensors ◽

10.1155/2012/483471 ◽

2012 ◽

Vol 2012 ◽

pp. 1-5 ◽

Cited By ~ 12

Author(s):

Anthony Lim ◽

Wen Bin Ji ◽

Swee Chuan Tjin

Keyword(s):

Refractive Index ◽

Cost Effective ◽

Experimental Results ◽

Refractive Index Sensitivity ◽

Long Period ◽

Specimen Collection ◽

Long Period Gratings ◽

Highly Sensitive ◽

Index Sensitivity

A new structure of Long-Period Gratings (LPGs) sensor is introduced as a sensitive ambient RI sensor. This structure consists of creating periodic corrugations on the cladding of the LPG. The experimental results show that this LPG structure has good performances in terms of linearity and sensitivity and serves as a highly sensitive and cost-effective sensor. It also has the advantage of portability as the corrugation can also serve as the reservoir for the specimen collection to be tested.

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The local surface plasmon resonance property and refractive index sensitivity of metal elliptical nano-ring arrays

AIP Advances ◽

10.1063/1.4901910 ◽

2014 ◽

Vol 4 (11) ◽

pp. 117115 ◽

Cited By ~ 1

Author(s):

Weihua Lin ◽

Qian Wang ◽

Qiuze Li ◽

Anhua Dong

Keyword(s):

Refractive Index ◽

Surface Plasmon Resonance ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Local Surface ◽

Resonance Property ◽

Refractive Index Sensitivity ◽

Local Surface Plasmon Resonance ◽

Index Sensitivity

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Improve the Hole Size-dependent Refractive Index Sensitivity of Au-Ag Nanocages by Tuning the Alloy Composition

10.21203/rs.3.rs-482206/v1 ◽

2021 ◽

Author(s):

Jianjun LI ◽

Qiu-Xiang Qin ◽

Guo-Jun Weng ◽

Jian Zhu ◽

Jun-Wu Zhao

Keyword(s):

Dielectric Constant ◽

Refractive Index ◽

Electric Field ◽

Alloy Composition ◽

Geometric Parameters ◽

Sensitivity Factor ◽

Hole Size ◽

Refractive Index Sensitivity ◽

Electric Field Direction ◽

Index Sensitivity

Abstract In this study, the nanoboxes is converted into Au-Ag alloy nanocages by increasing the hole size. Discrete dipole approximation (DDA) is used to study the extinction spectrum and the refractive index sensing characteristics of Au-Ag alloy nanocages with different geometric parameters. With the increase of Au component, the local surface plasmon resonance (LSPR) peak shows approximately linear redshift and the sensitivity factor shows approximately linear decrease. The refractive index sensitivity can be effectively controlled by the Au-Ag ratio at large hole size because the hole and cavity surfaces distribute more environmental dielectric components. Therefore, increasing the hole size and decreasing the Au-Ag ratio can improve the refractive index sensitivity. To explain the effect of alloy composition on the LSPR characteristics and the refractive index sensitivity, the local electric field distributions with different geometric parameters are plotted. We find that the electric field direction on the hole and cavity surfaces are controlled by the Au-Ag ratio and environmental dielectric constant. Moreover, the field vector on the hole and cavity surfaces are formed by the superposition of the incident field, the electric field generated by the oscillating electrons on the outer surface, and the polarized field in the environmental dielectric constant.

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