Optical lifting force under focused evanescent wave illumination: A ray optics model

2005 ◽  
Vol 97 (8) ◽  
pp. 083103 ◽  
Author(s):  
Smitha Kuriakose ◽  
Xiasong Gan ◽  
James W. M. Chon ◽  
Min Gu
Keyword(s):  
Evanescent Wave ◽  
Ray Optics ◽  
Lifting Force

X-ray microprobe for materials science

1994 ◽  
Vol 52 ◽  
pp. 56-57
Author(s):  
G.E. Ice
Keyword(s):  
Crystallographic Orientation ◽  
Local Structure ◽  
Materials Science ◽  
Chemical Information ◽  
X Ray Diffraction ◽  
Ray Optics ◽  
X Ray ◽  
Novel Materials ◽  
New Information ◽  
Elemental Sensitivity

The increasing availability of synchrotron x-ray sources has stimulated the development of advanced hard x-ray (E≥5 keV) microprobes. With new x-ray optics these microprobes can achieve micron and submicron spatial resolutions. The inherent elemental and crystallographic sensitivity of an x-ray microprobe and its inherently nondestructive and penetrating nature will have important applications to materials science. For example, x-ray fluorescent microanalysis of materials can reveal elemental distributions with greater sensitivity than alternative nondestructive probes. In materials, segregation and nonuniform distributions are the rule rather than the exception. Common interfaces to whichsegregation occurs are surfaces, grain and precipitate boundaries, dislocations, and surfaces formed by defects such as vacancy and interstitial configurations. In addition to chemical information, an x-ray diffraction microprobe can reveal the local structure of a material by detecting its phase, crystallographic orientation and strain.Demonstration experiments have already exploited the penetrating nature of an x-ray microprobe and its inherent elemental sensitivity to provide new information about elemental distributions in novel materials.

Aperiodic multilayer structures in soft X-ray optics

2015 ◽  
Vol 185 (11) ◽  
pp. 1203-1214 ◽  
Author(s):  
Aleksandr S. Pirozhkov ◽  
Evgenii N. Ragozin
Keyword(s):  
Multilayer Structures ◽  
Ray Optics ◽  
X Ray

Diffraction limited X-ray optics: technology, metrology, applications

2019 ◽  
Vol 190 (01) ◽  
pp. 74-91
Author(s):  
Nikolai I. Chkhalo ◽  
Ilya V. Malyshev ◽  
Alexey E. Pestov ◽  
Vladimir N. Polkovnikov ◽  
Nikolai N. Salashchenko ◽  
...  
Keyword(s):  
Ray Optics ◽  
X Ray

Simulation for enhancement in sensitivity of chalcogenide glasses-based fibre optic evanescent absorption sensor for malignant tissue detection

2020 ◽  
Vol 12 ◽  
Author(s):  
Ritesh Kumar Singh ◽  
Adarsh Chandra Mishra ◽  
Pooja Lohia ◽  
D.K. Dwivedi
Keyword(s):  
Evanescent Wave ◽  
Chalcogenide Glasses ◽  
Biological Tissues ◽  
Biological Species ◽  
Primary Objective ◽  
Effect Of Temperature ◽  
Refractive Indices ◽  
Core Radius ◽  
Source Illumination ◽  
Study Results

Background: Refractive index determination of biological tissues is a challenging issue. Many biological species also show vibrational signature in infrared domain. The chalcogenide-based glasses can be used to make the fiber optic evanescent wave sensors for detection of analyte. Objectives: The primary objective is to study the effect of various parameters on the sensitivity of chalcogenide glass-based evanescent wave sensor for biological tissue detection. Methods: An evanescent wave sensor has been proposed with collimated source illumination and uniform tapering. The chalcogenide materials are chosen such that the weakly guiding approximation could be followed. Complex refractive indices of liver tissue samples have been taken for the analysis of sensitivity via method of evanescent absorption coefficient. Equations for sensitivity have been solved analytically using MATLAB software. Results: The simplification of the formula for sensitivity leads to the inference that the sensitivity is a function of core radius, refractive indices of sample tissues and wavelength used. Moreover, since the refractive indices of the materials are also a function of temperature, therefore a change in temperature results into change in the profile of guiding mode. Hence the effect of temperature must also be observed. The initial simulation parameters are taken; core radius 100 µm, sensing length 4 cm and wavelength 1.0 µm. In the NIR region we have a better sensitivity of detection for all the tissues samples and the risk of photodamage of the biosamples is reduced to a good extent. It has been found that sensitivity decreases with wavelength and core radius whereas increases with temperature. It has also been shown that sensitivity is found to be better with collimated in comparison with diffused source. Conclusion: The comparative study results that one should operate at shorter NIR region of wavelength for higher sensitivity. The collimated source illumination should be preferred over diffused one for launching the light within the fiber to have high sensitivity. Further, length of sensing region should be larger but the fiber core radius should be smaller. The proposed biosensor is robust and can also be used many times if the probe (sensing region) is cleaned properly. Moreover, a small amount of analyte is enough for the detection. Thus, the proposed sensor is very useful for bio-medical applications with its high performance, accuracy and robustness.

Erratum to “Angle-Resolved Characterization and Ray-Optics Modeling of Fiber-Optic Sensors”

2021 ◽  
Vol 39 (1) ◽  
pp. 336-336
Author(s):  
George. Y. Chen ◽  
Christophe A. Codemard ◽  
Philip M. Gorman ◽  
Jaclyn S. Chan ◽  
Michalis N. Zervas
Keyword(s):  
Fiber Optic ◽  
Fiber Optic Sensors ◽  
Ray Optics

Detailed diffraction imaging of x-ray optics crystals with synchrotron radiation

2021 ◽  
Vol 92 (6) ◽  
pp. 063506
Author(s):  
N. R. Pereira ◽  
A. T. Macrander ◽  
E. Kasman ◽  
X.-R. Huang ◽  
E. O. Baronova
Keyword(s):  
Synchrotron Radiation ◽  
Ray Optics ◽  
X Ray ◽  
Diffraction Imaging

scholarly journals Unusual Polarization Relation between Single-Mode Lasing Emission and Excitation Laser from an Evanescent-Wave Pumped Micro-Cavity Laser

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 66
Author(s):  
Yuchen Wang ◽  
Hongsheng Li ◽  
Shu Hu ◽  
Heng Li ◽  
Chuanxiang Sheng
Keyword(s):  
Evanescent Wave ◽  
Single Mode ◽  
Transverse Magnetic ◽  
Ethanol Solution ◽  
Pump Laser ◽  
Fiber Axis ◽  
Lasing Threshold ◽  
Polarization Direction ◽  
Excitation Laser ◽  
Output Laser

Using a fiber of that is 125 μm in diameter in rhodamine 6G ethanol solution, controllable multi- and single-whispering-gallery-mode (WGM) optofluidic lasers based on evanescent-wave-coupled gain are both available. With multi-mode WGM emission, lasing emission with almost pure TM (transverse magnetic) or almost TE (transverse electric) modes can be obtained when the pump laser has an electric field parallel (perpendicular) to the fiber axis, i.e., the polarization direction of output laser is the same as that of the pump laser. On the other hand, when the laser emission is single-mode, the TE output laser always emerges firstly above lasing threshold, then keeps TE mode while the pump laser’s intensity increases with polarization direction perpendicular to the fiber axis; on the contrary, TE emission will dwindle relatively, while the TM emission emerges and dominates the spectra, when the pump laser’s intensity increases with polarization parallel to the fiber axis. Our work proves that controlling the leakage of the evanescent wave from high-Q microcavities is crucial for both modes of lasing emission and its polarization.

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