Determination of diameters and refractive indices of step-index optical fibres

1976 ◽  
Vol 12 (7) ◽  
pp. 155 ◽  
Author(s):  
P.L. Chu
Keyword(s):  
Refractive Indices ◽  
Optical Fibres ◽  
Step Index

Influence of measurement noise on the determination of the radial profile of the photoelastic coefficient in step-index optical fibers

2013 ◽  
Vol 52 (35) ◽  
pp. 8451 ◽  
Author(s):  
Sophie Acheroy ◽  
Patrick Merken ◽  
Heidi Ottevaere ◽  
Thomas Geernaert ◽  
Hugo Thienpont ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Radial Profile ◽  
Measurement Noise ◽  
Step Index

scholarly journals Refractive index evaluation of porous silicon using Bragg reflectors

2018 ◽  
Vol 64 (1) ◽  
pp. 72 ◽  
Author(s):  
D. Estrada-Wiese ◽  
J.A. Del Río
Keyword(s):  
Refractive Index ◽  
Porous Silicon ◽  
Simple Procedure ◽  
Merit Function ◽  
Refractive Indices ◽  
Bragg Reflectors ◽  
Photonic Bandgaps ◽  
Photonic Structures ◽  
Index Evaluation

There are two main physical properties needed to fabricate 1D photonic structures and form perfect photonic bandgaps: the quality of thethickness periodicity and the refractive index of their components. Porous silicon (PS) is a nano-structured material widely used to prepare 1Dphotonic crystals due to the ease of tuning its porosity and its refractive index by changing the fabrication conditions. Since the morphologyof PS changes with porosity, the determination of PS’s refractive index is no easy task. To find the optical properties of PS we can usedifferent effective medium approximations (EMA). In this work we propose a method to evaluate the performance of the refractive index ofPS layers to build photonic Bragg reflectors. Through a quality factor we measure the agreement between theory and experiment and thereinpropose a simple procedure to determine the usability of the refractive indices. We test the obtained refractive indices in more complicatedstructures, such as a broadband Vis-NIR mirror, and by means of a Merit function we find a good agreement between theory and experiment.With this study we have proposed quantitative parameters to evaluate the refractive index for PS Bragg reflectors. This procedure could havean impact on the design and fabrication of 1D photonic structures for different applications.

scholarly journals Parabolic Pulse Generation Using Tapered Microstructured Optical Fibres

2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
Natasha Vukovic ◽  
Neil G. R. Broderick ◽  
Francesco Poletti
Keyword(s):  
Pulse Shape ◽  
Pulse Shaping ◽  
Numerical Study ◽  
Pulse Generation ◽  
Optical Fibres ◽  
Step Index ◽  
Index Fibre ◽  
Microstructured Optical Fibres ◽  
Misfit Parameter ◽  
Better Than

This paper presents a numerical study of parabolic pulse generation in tapered microstructured optical fibres (MOFs). Based on our results and the algorithms presented, one can determine the linear taper profile (starting and finishing pitch values and taper length) needed to achieve parabolic pulse shaping of an initial Gaussian pulse shape with different widths and powers. We quantify the evolution of the parabolic pulse using the misfit parameter and show that it is possible to reach values significantly better than those obtained by a step index fibre.

Application of the Solution of the Inverse Light Scattering Problem for Characterization of Mononuclear Cells

2009 ◽  
Vol 4 (2) ◽  
pp. 61-68
Author(s):  
Dmitriy Strokotov ◽  
Yuriy Pichugin ◽  
Maxim Yurkin ◽  
Mariya Gridina ◽  
Oleg Serov ◽  
...  
Keyword(s):  
Stem Cells ◽  
Light Scattering ◽  
Mononuclear Cells ◽  
Human Lymphocytes ◽  
Scattering Problem ◽  
Refractive Indices ◽  
Single Particles ◽  
Differentiation Status

In this manuscript we propose two methods to solve inverse light scattering problem for single particles, which can be described as a coated sphere. The efficiency of the methods is illustrated by characterization of lymphocytes and stem cells using light scattering patterns obtained with scanning flow cytometer. Both methods, spectral and global optimization, were used to obtain diameters and refractive indices of the cytoplasm and the nucleus of mice embryo stem cells and human lymphocytes. These results agree with data obtained from other studies. Determination of these parameters is important for diagnostics of pathological states of lymphocytes and differentiation status of embryo stem cells. Moreover, methods described in this manuscript are applicable to all mononuclear cells. We also considered limitations of these methods and their possible improvements.

The petrology of the Mount Padbury mesosiderite and its achondrite enclaves

1966 ◽  
Vol 36 (276) ◽  
pp. 1029-1060 ◽  
Author(s):  
G. J. H. McCall
Keyword(s):  
Microscopic Analysis ◽  
Host Material ◽  
Refractive Indices ◽  
X Ray Diffraction ◽  
Thin Sections ◽  
X Ray ◽  
Wide Range ◽  
Varied Range ◽  
Optical Determination

SummaryThe petrography of the Mount Padbury meteorite, previously briefly recorded, is described in some detail. Both the metalliferous host material of the mesosiderite and the varied range of silicate-rich, virtually metal-free enclaves (including both familiar achondrite material and unfamiliar achondrite material) are described. Eucrite, brecciated eucrite, and a peculiar ‘shocked’ form of eucrite (resembling some terrestrial flaser-gabbros) are the calcium-rich achondrite types represented; hypersthene achondrite (including typical diogenite material and unfamiliar material) and olivine achondrite (granular aggregates of olivine not entirely similar to the unique chassignite and single crystals up to 4 in. in length) are the calcium-poor achondrite types represented. The eucrite displays more or less uniform mineralogy, but the mineral constituents are present in varying proportions, and there is a wide range of textural variations recognized. The silicate grain fragments enclosed in the metallic reticulation to form the mesosiderite host material are, significantly, entirely of minerals seen within the achondrite enclaves—plagioclase, hypersthene, pigeonite, olivine, and tridymite.These results include microscopic analysis of thin sections and polished sections, X-ray diffraction studies, optical determination of refractive indices using mineral grain mounts, and chemical analyses.The wider implications of this new and unique meteorite find are briefly considered.

Determination of refractive indices of liquids by Fresnel diffraction

2009 ◽  
Vol 41 (7) ◽  
pp. 892-896 ◽  
Author(s):  
Arash Sabatyan ◽  
Mohammad Taghi Tavassoly
Keyword(s):  
Fresnel Diffraction ◽  
Refractive Indices

scholarly journals THE REFRACTIVE INDICES OF WHOLE CELLS

1933 ◽  
Vol 17 (1) ◽  
pp. 41-47 ◽  
Author(s):  
E. S. Castle
Keyword(s):  
Focal Length ◽  
Refractive Indices ◽  
Radius Of Curvature ◽  
Whole Cells

Refractive indices of intact sporangiophores of Phycomyces were computed from measurements of focal length and radius of curvature of the cells. For the six cells studied, effective values of n were obtained ranging from 1.35 to 1.40. The average effective n was 1.38. Senn's determination of refractive indices of other plants cells gave much higher values: n = 1.37 to 1.52. The precision of the method and possible sources of this discrepancy are discussed.

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