scholarly journals Investigation of Factors Affecting Sensitivity Enhancement of an Optical Fiber Probe for Microstructure Measurement Using Oblique Incident Light

2020 ◽  
Vol 10 (9) ◽  
pp. 3191
Author(s):  
Hiroshi Murakami ◽  
Akio Katsuki ◽  
Takao Sajima ◽  
Kosuke Uchiyama ◽  
Ichiro Yoshida ◽  
...  
Keyword(s):  
Laser Beam ◽  
Optical Fiber ◽  
Measurement System ◽  
Incident Angle ◽  
Incident Light ◽  
Sensitivity Enhancement ◽  
Measurement Sensitivity ◽  
Factors Affecting ◽  
Accuracy Measurement ◽  
Experimental Apparatus

Recently, the demand for accuracy measurement of microstructures has been remarkable. We have been developing a measurement system for microstructures using a stylus made of an optical fiber and prisms. In this measurement system, the oblique irradiation of the laser beam was employed to detect the displacement of the stylus shaft generated by contact between the stylus tip and the measured surface, and to expand the measurable area and depth. After these evaluations, we discovered that the sensitivity was enhanced with the increase in the incident angle of the laser beam on the stylus shaft. Therefore, in this study, we focus on the effect of the incident angle of light on the measurement sensitivity. First, the enhancement sensitivity is confirmed by using the basic experimental apparatus. Next, the relationship between the incident angle of the laser beam and the sensitivity is theoretically examined using the 3D ray-tracing method. Finally, the factor of the sensitivity enhancement is analyzed using the same method. As a result, it was confirmed that the sensitivity was enhanced with the increase in the incident angle of the laser beam on the stylus shaft.

scholarly journals Phase Measurement of Guided-Mode Resonance Device Using Digital Micromirror Device Gratings

Photonics ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 136
Author(s):  
Min-Xu Chiang ◽  
Jaturon Tongpakpanang ◽  
Wen-Kai Kuo
Keyword(s):  
Phase Difference ◽  
Measurement System ◽  
Incident Angle ◽  
Incident Light ◽  
Phase Shifting ◽  
Digital Micromirror Device ◽  
Light Passing ◽  
Grating Pattern ◽  
Guided Mode ◽  
Guided Mode Resonance

This paper reports on the measurement system of the phase difference between s- and p-polarization components of the light passing through a guided-mode resonance (GMR) device using a digital micromirror device (DMD) gratings as a digital phase-shifting device. The phase of the non-zeroth order diffraction beams of the grating pattern displayed on the DMD can exhibit a phase change when the grating pattern is shifted. Two nearest different diffraction orders of p-polarized and s-polarized beams can be used as the reference and measurement beams, respectively, and are combined to implement the phase-shifting interferometry (PSI). The phase difference between the s- and the p-polarization components of the incident light passing through the GMR device can be obtained by applying the four-step phase-shift algorithm to the DMD-based PSI system. Experimental results show that this measurement system has a phase detection limit of 1° and was able to obtain the abrupt phase difference curve of the GMR device versus the incident angle.

scholarly journals Plasmonic linear nanomotor using lateral optical forces

2020 ◽  
Vol 6 (45) ◽  
pp. eabc3726
Author(s):  
Yoshito Y. Tanaka ◽  
Pablo Albella ◽  
Mohsen Rahmani ◽  
Vincenzo Giannini ◽  
Stefan A. Maier ◽  
...  
Keyword(s):  
Laser Beam ◽  
Incident Light ◽  
Lateral Force ◽  
Diffraction Limit ◽  
Propagation Direction ◽  
Optical Force ◽  
Optical Forces ◽  
Incident Laser ◽  
New Class ◽  
Force Direction

Optical force is a powerful tool to actuate micromachines. Conventional approaches often require focusing and steering an incident laser beam, resulting in a bottleneck for the integration of the optically actuated machines. Here, we propose a linear nanomotor based on a plasmonic particle that generates, even when illuminated with a plane wave, a lateral optical force due to its directional side scattering. This force direction is determined by the orientation of the nanoparticle rather than a field gradient or propagation direction of the incident light. We demonstrate the arrangements of the particles allow controlling the lateral force distributions with the resolution beyond the diffraction limit, which can produce movements, as designed, of microobjects in which they are embedded without shaping and steering the laser beam. Our nanomotor to engineer the experienced force can open the door to a new class of micro/nanomechanical devices that can be entirely operated by light.

One-Dimensional Diffraction Grating of Poly(Methacrylic Acid) Brushes For The Rapid Label-Free Detection of Yersinia Pestis With a Reflective Laser System

2021 ◽  
Author(s):  
Feng-Ping Lin ◽  
Hui-Ling Hsu ◽  
Hui-Chung Lin ◽  
Hsin-Hsien Huang ◽  
Chien-Hsing Lu ◽  
...  
Keyword(s):  
Laser Beam ◽  
Yersinia Pestis ◽  
Methacrylic Acid ◽  
Limit Of Detection ◽  
Incident Angle ◽  
Diffraction Effect ◽  
Label Free ◽  
Diffraction Intensity ◽  
One Dimensional ◽  
Label Free Detection

Abstract Background: Because of the low sensitivity of commercial products, development of a facile method to rapidly identify plague on-site remains highly attractive. Line arrays of poly(methacrylic acid) (PMAA) brushes were grafted using a photoresist template to fabricate one-dimensional diffraction gratings (DGs). The as-prepared samples first bound protein G to immobilize and orient the tails of the antibody of Yersinia pestis (abY). A laser beam was employed to analyze the 2D and 3D reflective signals of DGs at an incident angle of 45°. The abY-tailed PMAA DG possessed an optical feature with a characteristic diffraction effect along the SII, in which the projection of the laser beam on the plane of the DG chip was parallel to the strips, and ST configurations, in which they were perpendicular. A fluidic diffraction chip based on the abY-tailed PMMA DG was fabricated to examine the ability to detect Yersinia pestis along the ST configuration. Results: Upon flowing through the chip, Yersinia pestis was attached to the abY-tailed PMMA DG, which changed the diffraction intensity. The degree of the diffraction intensity exhibited a linear response to Yersinia pestis at concentrations from 102 to 107 CFU mL−1, and the limit of detection was 75 CFU mL−1, 1000 times lower than a commercial product (Alexter Bio-Detect Test). The diffractive sensor could selectively detect Yersinia pestis in spiked serum samples, with excellent standard deviation and recovery. Conclusion: Our platform provides a simple, label-free method for on-site plague diagnosis to prevent the highly rapid transmission of plague.

Optical Analysis of Hole Patterned Ag Nanoparticle Structure

2021 ◽  
Vol 21 (8) ◽  
pp. 4192-4199
Author(s):  
Hyun-Ji Jeon ◽  
Ji-Yeon Kim ◽  
Jinnil Choi
Keyword(s):  
Metal Nanoparticles ◽  
Optical Transmission ◽  
Incident Angle ◽  
Incident Light ◽  
Localized Surface Plasmon ◽  
Optical Analysis ◽  
Optical Noise ◽  
Hole Configuration ◽  
Nanoparticle Structure ◽  
Sub Wavelength

A structure with periodic sub-wavelength nanohole patterns interacts with incident light and causes extraordinary optical transmission (EOT), with metal nanoparticles leading to localized surface plasmon resonance (LSPR) phenomena. To explore the effects of metal nanoparticles (NPs), optical analysis is performed for metal NP layers with periodic hole patterns. Investigation of Ag NP arrangements and comparisons with metal film structures are presented. Ag NP structures with different hole configuration are explored. Also, the effects of increasing light incident angle are investigated for metal NP structures where EOT peak at 460 nm wavelength is observed. Moreover, electric field distributions at each transmittance peak wavelengths and optical noise are analyzed. As a result, optical characteristics of metal NP structures are obtained and differences in resonance at each wavelength are highlighted.

Theoretical Analysis of Sensitivity Enhancement by Graphene Usage in Optical Fiber Surface Plasmon Resonance Sensors

2019 ◽  
Vol 68 (5) ◽  
pp. 1554-1560 ◽  
Author(s):  
Arthur Aprigio de Melo ◽  
Talita Brito da Silva ◽  
Marcia Fernanda da Silva Santiago ◽  
Cleumar da Silva Moreira ◽  
Rossana Moreno Santa Cruz
Keyword(s):  
Surface Plasmon Resonance ◽  
Theoretical Analysis ◽  
Optical Fiber ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Fiber Surface ◽  
Sensitivity Enhancement ◽  
Surface Plasmon Resonance Sensors

Novel Measurement System With Optical Fiber Sensor for Strain Distributions in Welded Tubular Joints

2008 ◽  
Author(s):  
Hideaki Murayama ◽  
Kazuro Kageyama ◽  
Kohei Ohara ◽  
Kiyoshi Uzawa ◽  
Makoto Kanai ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Spatial Resolution ◽  
Measurement System ◽  
Strain Distribution ◽  
Welded Joint ◽  
Optical Fiber Sensor ◽  
Weld Line ◽  
Fiber Sensor ◽  
Strain Monitoring ◽  
Tubular Joint

Defects and damage in a structural joint can trigger a critical degradation or collapse of the structure. Among joints, welded joints have many uncertainties, such as remaining stress, initial defects, and heat-affected zone. Such uncertainties in a welded joint can also induce a strain fluctuation, when they are subjected to a load. Conversely, the strain fluctuation along the weld line may represent the presence of uncertainties in the welded joint. This means that monitoring strain distribution along the weld line can be good way to assess their integrity and improve reliability of the structure. We have developed a novel distributed strain measurement technique which can measure strain distributions along fiber Bragg gratings (FBG) in an optical fiber and has the high spatial resolution and we applied it to strain monitoring of a welded tubular joint. The spatial resolution o is less than 1 mm and it was confirmed by measurement simulations and experiments. Then, we measured the strain distributions along the weld line of the tubular joint of a steel pipe subjected to a tensile load by the developed measurement system. We could successfully measure the development of the strain distribution along the weld line, where the sharply fluctuating strain distributions resulting from some defects were observed. In this paper, we describe the measurement principle and performance of the optical fiber sensor, and then show the results of strain monitoring in the welded joint.

Development of a 3D Vision Coordinates Measurement System Using Planar Target

2011 ◽  
Vol 383-390 ◽  
pp. 5182-5187
Author(s):  
Qiang Fu ◽  
Hong Zhao ◽  
Nan Cao ◽  
Jin Jun Li
Keyword(s):  
Measurement System ◽  
Hot Spot ◽  
Geometric Model ◽  
Geometric Transformation ◽  
Three Dimension ◽  
3D Vision ◽  
Factors Affecting ◽  
Detail Design ◽  
Binocular Stereo Vision ◽  
Planar Target

Three-dimension vision coordinates measurement presents many virtues such as high accuracy, flexible construction, simple operation, large measuring range and high measuring speed. So it has become a hot spot of application and research in many fields such as manufacturing, reverse engineering and computer aided surgery. In this paper, a 3D vision coordinates measurement system based on binocular stereo vision and a planar target has been designed and set up. The system’s composing and measuring principles are discussed. The geometric model and detail design of the planar target, which is one of the main factors affecting the system’s measuring stability and accuracy, are presented. A new algorithm for target calibration is proposed. The location and orientation of the planar target can be reconstructed according to rigid geometric transformation. Further results of calibration and measurement are verified experimentally, and a high geometrical accuracy can be achieved.

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