Journal ArticleDOI
Axial refractive index depression in preforms and fibers
TLDR
In this article, the refractive index depression that exists along the axis in modified chemical vapor deposited (MCVD) preforms and fibers doped mainly with GeO2 or P2O5 is studied by interference microscopy.Abstract:
The refractive index depression that exists along the axis in modified chemical vapor deposited (MCVD) preforms and fibers doped mainly with GeO2 or P2O5 is studied by interference microscopy. The index profile of a preform, determined as a function of its transition from the uncollapsed to the fully collapsed state, shows that this central region is fully depleted of dopant and has an index value corresponding to that of the pure fused silica cladding. The same results are found in samples taken from six preform tips and from a relatively large fiber, indicating that this effect is a general property of an uncompensated fabrication process. Implications for its influence on the fiber's transmission properties are discussed.read more
Citations
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Journal ArticleDOI
Calculation of bandwidth from index profiles of optical fibers. 1: Theory
TL;DR: This paper describes a method for calculating the impulse response and bandwidth of multimode optical fibers from measured refractive-index profiles obtained either from the fiber itself or from its preform, based on the WKB solution of the guided-mode problem.
Journal ArticleDOI
Rapid automatic index profiling of whole-fiber samples: Part II
TL;DR: In this article, a method for determining the refractive index profiles of optical fibers is presented, where the whole fiber is immersed in index-matching oil and placed transversely under an interference microscope.
Journal ArticleDOI
Nondestructive measurement of refractive-index profile and cross-sectional geometry of optical fiber preforms
TL;DR: A modified focusing method for measuring simultaneously the refractive-index profile and the cross-sectional geometry of an optical fiber preform is presented and it was found that the error of the index profile measurement was <1%.
Journal ArticleDOI
Effects of profile deformations on fiber bandwidth.
TL;DR: This paper studies the influence on bandwidth of a number of refractive-index deformations commonly encountered in preform manufacture and demonstrates that the theoretically realizable bandwidth of about 11,000 MHz is reduced to several hundred MHz.km for many of these deviations.
Journal ArticleDOI
Index profile measurements of fibers and their evaluation
D. Marcuse,H.M. Presby +1 more
TL;DR: In this paper, the authors discuss methods for measuring the refractive index distribution in optical fibers and for predicting their impulse response and signal bandwidth from the measured profiles, and some attention is also given to preform and single-mode fiber profiling.
References
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Journal ArticleDOI
A new technique for the preparation of low-loss and graded-index optical fibers
TL;DR: In this paper, a method for producing waveguides having a GeO 2 -SiO 2 core and SiO 2 cladding is described, which combine low loss with relatively large index differences between core and cladding.
Journal ArticleDOI
Pulse broadening caused by deviations from the optimal index profile
TL;DR: The excess pulse broadening caused by deviations from the optimal index profile is analyzed for multimode optical fibers and the type and degree of index profile control required to keep the pulses broadening below a specified level is indicated.
Journal ArticleDOI
Refractive index profiling of graded index optical fibers
TL;DR: In this paper, a method of determining the refractive index distribution of graded-index optical fibers based on interference microscopy is described, and sample preparation techniques, observational methods, and data reduction and analysis by a computer fitting program are described.
Journal ArticleDOI
Automatic analysis of interferograms: optical waveguide refractive index profiles.
TL;DR: A machine aided method for analysis of interference micrographs for the rapid determination of optical waveguide refractive index profiles using a scanning microdensitometer and computer determination of the position of the center line of each fringe.
Journal ArticleDOI
Novel technique for measuring the index profile of optical fibers
J. A. Arnaud,R. M. Derosier +1 more
TL;DR: In this paper, a novel technique for measuring the refractive index profile of optical fibers is demonstrated, which offers substantial advantages over alternative methods, such as interferometric measurements, illumination of a small area of the fiber core and measuring the total transmitted power.