Lithography-free and Highly Angle Sensitive Structural Coloration Using Fabry–Perot Resonance of Tin

AbstractRecently, there has been much interest in applying the color changes of nano-patterned structures to sensor technology. However, the lithographic nano-patterning process is not environmentally friendly, and it is difficult to fabricate large areas of color due to limitations associated with this approach. In this study, we realized a highly tunable structural coloration based on a Fabry–Perot interferometer design that does not require nano-patterning processes. To increase the reflected color change according to the angle, a color element using an asymmetric metal–insulator–metal structure was applied, fabricated using silver–silicon dioxide–tin (Sn), respectively. Using the optical properties of Sn, we maximized the change in reflection color and realized three primary colors of subtractive color of cyan, magenta and yellow according to the angle of designed MIM structure. Theoretical and experimental results revealed that the color and intensity of the reflectance depended strongly on the angle of the reflective surfaces. The manufacturing process is simple and yields large surfaces of high quality. Based on this premise, we fabricated a soft robot capable of color camouflage, and an angle-detecting color sensor for inspecting the three-dimensional shape quality of curved glass with a high sensitivity of 1.8 nm/degree. In addition, we propose a shape evaluation method by color, spectrometry, and monochromatic light.

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Design of a Liquid-Crystal-Tunable Terahertz Demultiplexer Based on a Metal-Insulator-Metal Waveguide

Applied Sciences ◽

10.3390/app9040644 ◽

2019 ◽

Vol 9 (4) ◽

pp. 644

Author(s):

Xue-Shi Li ◽

Naixing Feng ◽

Yuan-Mei Xu ◽

Liang-Lun Cheng ◽

Qing Liu

Keyword(s):

Liquid Crystal ◽

Electric Field ◽

Metal Insulator ◽

Resonance Modes ◽

External Bias ◽

Bias Electric Field ◽

Metal Waveguide ◽

Metal Insulator Metal ◽

Fabry Perot ◽

Mim Waveguide

A tunable demultiplexer with three output channels infiltrated by liquid crystal (LC) is presented, which is based on a metal-insulator-metal (MIM) waveguide. The operating frequencies of the three output channels can be tuned simultaneously at will by changing the external bias electric field applied to the LC. By analyzing the Fabry-Pérot (FP) resonance modes of the finite-length MIM waveguide both theoretically and numerically, the locations of the three channels are delicately determined to achieve the best demultiplexing effects. Terahertz (THz) signals input from the main channel can be demultiplexed by channels 1, 2 and 3 at 0.7135 THz, 1.068 THz and 1.429 THz, respectively. By applying an external electric field to alter the tilt angle of the infiltrating LC material, the operating frequencies of channels 1, 2 and 3 can be relatively shifted up to 12.3%, 9.6% and 9.7%, respectively. The designed demultiplexer can not only provide a flexible means to demultiplex signals but also tune operating bands of output channels at the same time.

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Photogrammetric Digital Surface Model Reconstruction in Extreme Low-Light Environments

Remote Sensing ◽

10.3390/rs13071261 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1261

Author(s):

Riccardo Roncella ◽

Nazarena Bruno ◽

Fabrizio Diotri ◽

Klaus Thoeni ◽

Anna Giacomini

Keyword(s):

Image Quality ◽

Image Quality Assessment ◽

High Sensitivity ◽

Sensor Technology ◽

Surface Model ◽

Night Time ◽

Low Light ◽

Reduction Techniques ◽

Geometrical Information ◽

Imaging Sensors

Digital surface models (DSM) have become one of the main sources of geometrical information for a broad range of applications. Image-based systems typically rely on passive sensors which can represent a strong limitation in several survey activities (e.g., night-time monitoring, underground survey and night surveillance). However, recent progresses in sensor technology allow very high sensitivity which drastically improves low-light image quality by applying innovative noise reduction techniques. This work focuses on the performances of night-time photogrammetric systems devoted to the monitoring of rock slopes. The study investigates the application of different camera settings and their reliability to produce accurate DSM. A total of 672 stereo-pairs acquired with high-sensitivity cameras (Nikon D800 and D810) at three different testing sites were considered. The dataset includes different camera configurations (ISO speed, shutter speed, aperture and image under-/over-exposure). The use of image quality assessment (IQA) methods to evaluate the quality of the images prior to the 3D reconstruction is investigated. The results show that modern high-sensitivity cameras allow the reconstruction of accurate DSM in an extreme low-light environment and, exploiting the correct camera setup, achieving comparable results to daylight acquisitions. This makes imaging sensors extremely versatile for monitoring applications at generally low costs.

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Research to Health Diagnose Model of Gate and Hoist Machinery Based on AHP

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.287-290.3036 ◽

2011 ◽

Vol 287-290 ◽

pp. 3036-3042 ◽

Cited By ~ 4

Author(s):

Guang Ming Yang ◽

Wen Bin Jia

Keyword(s):

Evaluation Method ◽

Safety Evaluation ◽

Metal Structure ◽

Weight Coefficient ◽

Diagnostic Model ◽

Ahp Method ◽

Safety Level ◽

Comprehensive Health ◽

Expert Evaluation Method ◽

Health Diagnosis

Safety evaluation index is a fundamental and key element in composing hydraulic metal structure healthy diagnostic model, however,the determination of weighting of Indexes is closely related to the reasonability and reliability of the whole evaluation result.Based on the safety level, importance and expertise of the main factors on hydraulic metal structure,we also combine integration of AHP method of nine marks and expert evaluation method to determine the weight coefficient of each index, the comprehensive health diagnosis of gates and hoists based on AHP method are first constructed in line with scientific and rational principles .And we use the model to achieve the specific project safety evaluation of hydraulic metal structures, also comparing it with the traditional comparative analysis, proving the comprehensive health diagnosis based on AHP model to be a more scientific, reasonable and reliable one.

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Strong fiber Bragg grating based asymmetric Fabry–Perot sensor system with multiple reflections for high sensitivity enhancement

Optical Fiber Technology ◽

10.1016/j.yofte.2013.12.009 ◽

2014 ◽

Vol 20 (2) ◽

pp. 95-99 ◽

Cited By ~ 3

Author(s):

Wei Wang ◽

Zhengliang Hu ◽

Mingxiang Ma ◽

Huizu Lin ◽

Yongming Hu

Keyword(s):

Fiber Bragg Grating ◽

High Sensitivity ◽

Sensitivity Enhancement ◽

Sensor System ◽

Bragg Grating ◽

Multiple Reflections ◽

Fabry Perot

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High-sensitivity quasi-distributed temperature sensors based on weak FBGs Fabry-Perot structure with metal coating

2017 16th International Conference on Optical Communications and Networks (ICOCN) ◽

10.1109/icocn.2017.8121290 ◽

2017 ◽

Author(s):

Minghong Yang ◽

Kun Yang ◽

Jianguan Tang ◽

Chengli Li ◽

Fufa Shang

Keyword(s):

High Sensitivity ◽

Temperature Sensors ◽

Metal Coating ◽

Fabry Perot ◽

Distributed Temperature Sensors

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Improved Refractive Index-Sensing Performance of Multimode Fano-Resonance-Based Metal-Insulator-Metal Nanostructures

Nanomaterials ◽

10.3390/nano11082097 ◽

2021 ◽

Vol 11 (8) ◽

pp. 2097

Author(s):

Yuan-Fong Chou Chau ◽

Chung-Ting Chou Chao ◽

Siti Zubaidah Binti Haji Jumat ◽

Muhammad Raziq Rahimi Kooh ◽

Roshan Thotagamuge ◽

...

Keyword(s):

Refractive Index ◽

Plasmon Resonance ◽

Fano Resonance ◽

High Sensitivity ◽

Metal Nanostructures ◽

Refractive Index Sensor ◽

Metal Insulator ◽

Wide Range ◽

Metal Insulator Metal ◽

Mode 2

This work proposed a multiple mode Fano resonance-based refractive index sensor with high sensitivity that is a rarely investigated structure. The designed device consists of a metal–insulator–metal (MIM) waveguide with two rectangular stubs side-coupled with an elliptical resonator embedded with an air path in the resonator and several metal defects set in the bus waveguide. We systematically studied three types of sensor structures employing the finite element method. Results show that the surface plasmon mode’s splitting is affected by the geometry of the sensor. We found that the transmittance dips and peaks can dramatically change by adding the dual air stubs, and the light–matter interaction can effectively enhance by embedding an air path in the resonator and the metal defects in the bus waveguide. The double air stubs and an air path contribute to the cavity plasmon resonance, and the metal defects facilitate the gap plasmon resonance in the proposed plasmonic sensor, resulting in remarkable characteristics compared with those of plasmonic sensors. The high sensitivity of 2600 nm/RIU and 1200 nm/RIU can simultaneously achieve in mode 1 and mode 2 of the proposed type 3 structure, which considerably raises the sensitivity by 216.67% for mode 1 and 133.33% for mode 2 compared to its regular counterpart, i.e., type 2 structure. The designed sensing structure can detect the material’s refractive index in a wide range of gas, liquids, and biomaterials (e.g., hemoglobin concentration).

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