Optics and Laser Technology
(Elsevier)
• 02 Nov 2018
Simović, Ana • Savović, Svetislav • Drljača, Branko • Djordjevich, Alexandar
We propose a multimode W type (doubly clad) plastic optical fiber which takes the characteristic W-shaped index profile designed from a multimode singly clad step index plastic optical fiber upon modification of the cladding layer of the latter. For different widths of the inner cladding and refractive index of the outer cladding, the bandwidth and steady-state loss are determined for such W type plastic optical fiber. We have shown that bandwidth of W type plastic optical fiber is significantly ...
Optics and Laser Technology
(Elsevier)
• 04 Apr 2018
Savović, Svetislav • Djordjevich, Alexandar • Simović, Ana • Drljača, Branko
We investigate the influence of mode coupling on space division multiplexing capability of three multimode step-index plastic optical fibers with different strengths of mode coupling. Results show that mode
coupling significantly limits the fiber length at which the space division multiplexing can be realized with
a minimal crosstalk between the neighbor optical channels. Three, four and five spatially multiplexed
channels in the investigated multimode step-index plastic optical fibers can be ...
Photonics
(MDPI)
• 23 Feb 2022
Savović, Svetislav • Djordjevich, Alexandar • Savović, Isidora • Drljača, Branko • Simović, Ana • Min, Rui
We studied the effect of mode coupling on the space division multiplexing (SDM) capabilities of multimode step-index (SI) air-clad silica optical fibers by numerically solving the power
flow equation. Mode coupling considerably reduces the length of these fibers at which space division multiplexing may be achieved with minimal crosstalk between neighboring optical channels,
according to the findings. Up to 120 m and 30 m, respectively, the two and three spatially multiplexed channels in the ...
Photonics
(MDPI)
• 23 Mar 2022
Drljača, Branko • Savović, Svetislav • Kovačević, Milan • Simović, Ana • Kuzmanović, Ljubica • Djordjevich, Alexandar • Min, Rui
Solving the time-dependent power flow equation (PFE) provides a useful method to study
the transmission bandwidth of step-index silica photonic crystal fibers (SI SPCFs). The transmission
bandwidth of these kinds of fibers is determined for different air-hole structures (different numerical apertures (NAs)) and different distribution widths of the Gaussian launch beam. The results
indicate that the lower the NA of SI SPCFs, the higher the bandwidth (for example, for a lower NA
of SI SPCF ...
Optik
(Elsevier)
• 21 Aug 2021
Savović, Svetislav • Kovačević, Milan • Drljača, Branko • Simović, Ana • Kuzmanović, Ljubica • Djordjevich, Alexandar
We investigate the state of mode coupling in a multimode step-index plastic photonic crystal fiber
(SI PPCF) with a solid-core by solving the time-independent power flow equation. For various
arrangements of air-holes, and therefore a different numerical apertures (NAs), as well as a
different widths of launch beam distribution, the length Lc for achieving equilibrium mode distribution (EMD) and length zs at which a steady state distribution (SSD) is established are
determined for such f ...
Optik
(Elsevier)
• 30 Jul 2021
Savović, Svetislav • Kovačević, Milan • Simović, Ana • Kuzmanović, Ljubica • Drljača, Branko • Djordjevich, Alexandar
We propose a new method for investigation the state of mode coupling in a multimode step-index
silica photonic crystal fiber (SI SPCF) with a solid-core by solving the time-independent power
flow equation. For various arrangements of air-holes (different numerical apertures (NAs)), as
well as a different widths of launch beam distribution, the length Lc for achieving equilibrium
mode distribution (EMD) and length zs at which a steady state distribution (SSD) is established are
determin ...
Ricerche di Matematica
(Springer)
• 26 Oct 2021
Savović, Svetislav • Drljača, Branko • Djordjevich, Alexandar
An unconditionally-positive finite difference (UPFD) and the standard explicit finite difference schemes are compared to the analytical solution of the advection–diffusion reaction equation which describes the exponential traveling wave in heat and mass transfer processes. It is found that although the unconditional positivity of the UPFD scheme, this scheme is less accurate than the standard explicit finite difference scheme. This is because the UPFD scheme contains additional truncation-error ...
Optik - International Journal for Light and Electron Optics
(Elsevier)
• 08 Aug 2021
Simović, Ana • Savović, Svetislav • Drljača, Branko • Djordjevich, Alexandar
This paper investigates the wavelength dependence of the equilibrium mode distribution (EMD)
and steady state distribution (SSD) in W-type plastic optical fibers (POFs) with graded index (GI)
core distribution for parametrically varied width of the fiber’s intermediate optical layer and
refractive index of the outer cladding. The numerical solution of the time-independent power flow
equation is used to determine the transmission characteristics of the W-type GI POF. We
demonstrated tha ...
27th Telecommunications forum TELFOR 2019
(27th Telecommunications forum TELFOR 2019)
• 27 Nov 2019
Marković, Aleksandar • Perić, Zoran • Panić, Stefan
The closed-form expression for Q-function does not exist so it is necessary to develop its approximation in order to overcome the difficulties that might appear in diverse
research areas. In this paper the authors are presenting overview of two improved models for Q-function approximation with wide applicability. The first one is based
on Karagiannidis and Mils model and the second one is based on Borjesson model to obtain the desired improved form of Qfunction approximation.
Optical Fiber Technology
(Elsevier)
• 27 Nov 2019
Drljača, Branko • Simović, Ana • Djordjevich, Alexandar • Savović, Svetislav
Wavelength dependence of equilibrium mode distribution (EMD) and steady state distribution (SSD) in W-type
plastic-clad silica fibers (PCSFs) is investigated in this paper for parametrically varied width of the fiber’s intermediate optical layer and refractive index of the outer cladding. We have shown that the W-type PCSF has
better transmission characteristics at longer infrared wavelengths. This is explained by the rise of the leaky mode
losses with increasing wavelength. This facilitates ...
