scholarly journals Parity time-symmetric vertical cavities: intrinsically single-mode regime in longitudinal direction

2016 ◽  
Vol 24 (15) ◽  
pp. 17125 ◽  
Author(s):  
Hugh F. Jones ◽  
Mykola Kulishov ◽  
Bernard Kress
Keyword(s):  
Single Mode ◽  
Longitudinal Direction ◽  
Single Mode Regime

scholarly journals Principles of Automated Data Processing of Mandelstam – Brillouin Backscatter Characteristics for Evaluating the State of Optical Fibers

T-Comm ◽  
2020 ◽  
Vol 14 (8) ◽  
pp. 47-52
Author(s):  
Igor V. Bogachkov ◽  
Keyword(s):  
Optical Fibers ◽  
Light Guide ◽  
Functional Dependence ◽  
Single Mode ◽  
Longitudinal Direction ◽  
The State ◽  
Normal Operation ◽  
Fiber Types ◽  
Operational Parameters ◽  
Acoustic Modes

For early diagnostics of the state of optical fibers (OFs) located in the laid optical cables (OCs), it is necessary to identify potentially unreliable sections of the S in advance, which over time can lead to the destruction of fibers and disrupt the normal operation of fiber-optic communication lines (FOCLs). For diagnosis and forecasting of the state of the OFs that are in the laid OCs, Brillouin optical pulse reflectometers (BOTDR) are used, in which the back-reflected signal of the spontaneous Mandelstam – Brillouin scattering (MBS) is analyzed. In the process of obtaining a trace of the distribution of the Mandelshtam – Brillouin backscatter spectrum (MBBS) along the OF, the Brillouin frequency shift (BFS) is determined. After this, a graphs of the distribution of strain along the light-guide is constructed. A classification of varieties of single-mode optical fibers based on analysis of the MBS characteristics is discussed in this paper. It is shown how by the characteristics of the frequency profiles of the MBBS, one can determine the type of fiber and also evaluate the change in the strain and BFS. The MBBS profile come under influence by the functional dependence of the distribution of acoustic modes in the OF, their longitudinal direction. Both of them depend on the structure of the OF layers, as well as on the types and concentration of various alloying additives of the core OF. For single-mode OFs, when describing the MBS process, it is necessary to take into account the spatial distribution and interaction of the main optical and several acoustic modes. After uploading the data file from the BOTDR, it is necessary to process the information in order to determine the BFS and the strain along the light-guide. This process can be automatized, if a database has been formed. When a new Brillouin reflectogram appears, the MBBS profile from it must be compared with templates from the generated database. To classify the fiber types, it is necessary to evaluate the degree of matching of the explored MBBS profile with all the database templates. To assess the degree of coincidence of the considered MBBS profiles, needs to be defined the overall part of the frequency band for analysis. The programs for the automated processing of the Brillouin reflectograms data are presented. Based on the analysis of Brillouin reflectograms, it is possible to identify a factor that had a predominant influence on the characteristics of the MBS signal in the explored sections of single-mode optical fibers. As a result of the program's work, a template is output that, according to the program's estimates according to the algorithm described above, has the best match with the downloaded image. To increase the accuracy of assessing the similarity of the explored profiles, it is also recommended to carry out calculations according to the above-described algorithm when aligning not only the maximum levels, but also combine the graphs along the frequency axis. It is clear that during the overlay the frequencies of the "peaks" (BFS), there will be a very strong coincidence of the patterns, and the type of the OFs will be determined correctly, while at some temperatures a good degree of similarity with another pattern could be obtained. The obtained estimate of the BFS allows one to determine the degree of the OF strain. The identification of the MBBS profile and other characteristics of the MBS allows you to create a database various types of the OFs and different manufacturers, which can be used to classify the type of the OFs. The results presented in this exploratory development show how based on the analysis of BOTDR reflectograms, it is possible to automatically determine the type of the OF in OC, to identify a factor that has a predominant effect on the frequency response and strain in the explored sections of the OFs in FOCL, which can improve the efficiency of predicting the operational parameters of the physical channels of optical telecommunication systems.

Thermal Effects on the Single-Mode Regime of Distributed Modal Filtering Rod Fiber

2012 ◽  
Vol 30 (22) ◽  
pp. 3494-3499 ◽  
Author(s):  
Enrico Coscelli ◽  
Federica Poli ◽  
Thomas Tanggaard Alkeskjold ◽  
Mette Marie Jorgensen ◽  
Lasse Leick ◽  
...  
Keyword(s):  
Thermal Effects ◽  
Single Mode ◽  
Single Mode Regime

scholarly journals Single-Mode Regime in Large-Mode-Area Rare-Earth-Doped Rod-Type PCFs

2009 ◽  
Vol 15 (1) ◽  
pp. 54-60 ◽  
Author(s):  
F. Poli ◽  
A. Cucinotta ◽  
D. Passaro ◽  
S. Selleri ◽  
J. Laegsgaard ◽  
...  
Keyword(s):  
Rare Earth ◽  
Single Mode ◽  
Large Mode Area ◽  
Mode Area ◽  
Single Mode Regime ◽  
Rare Earth Doped

Saturation effects at backward-stimulated scattering in the single-mode regime of interaction

1989 ◽  
Vol 21 (5) ◽  
pp. 381-395 ◽  
Author(s):  
E. M. Dianov ◽  
A. Ya. Karasik ◽  
A. V. Lutchnikov ◽  
A. N. Pilipetskii
Keyword(s):  
Single Mode ◽  
Stimulated Scattering ◽  
Saturation Effects ◽  
Single Mode Regime

scholarly journals Waveguide T-junctions with resonant coupling between sections of different dimensions

2016 ◽  
Vol 9 (5) ◽  
pp. 1059-1065 ◽  
Author(s):  
Sergey L. Berdnik ◽  
Victor A. Katrich ◽  
Mikhail V. Nesterenko ◽  
Yuriy M. Penkin
Keyword(s):  
Single Mode ◽  
Physical Parameters ◽  
Energy Characteristics ◽  
Resonant Coupling ◽  
Variable Surface ◽  
Arbitrary Position ◽  
Rectangular Waveguides ◽  
Electromagnetic Characteristics ◽  
End Wall ◽  
Single Mode Regime

Electromagnetic characteristics of the E-plane T-junction for two rectangular waveguides using resonant coupling between the waveguide sections were studied by mathematical modeling. The problem of coupling between infinite and semi-infinite rectangular waveguides through a resonant slot in the end-wall of the semi-infinite waveguide in the presence of resonant monopole is solved in a strict electrodynamic formulation. The monopole with variable surface impedance is placed parallel to the narrow walls at an arbitrary position inside the infinite waveguide. The problem is solved analytically by the generalized method of induced electro-magneto-motive forces. Impedance vibrator inclusions with variable electro-physical parameters have been analyzed as control elements for waveguide junctions. To this purpose energy characteristics of the junction in the single-mode regime of the both waveguides, and also in multi-mode regime of the semi-infinite waveguide is investigated. The results may be useful for development of variety antennas and waveguide devices, which involves waveguide junctions.

Single-mode regime of 19-cell Yb-doped double-cladding photonic crystal fibers

2011 ◽  
Author(s):  
Enrico Coscelli ◽  
Federica Poli ◽  
Thomas T. Alkeskjold ◽  
Davide Passaro ◽  
Annamaria Cucinotta ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystal Fibers ◽  
Single Mode ◽  
Crystal Fibers ◽  
Single Mode Regime
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