Methodology Article
Chromatic Dispersion Modeling in Optical Fiber Transmission Systems
Randriana Heritiana Nambinina Erica*
,
Ando Nirina Andriamanalina
Issue:
Volume 11, Issue 1, June 2026
Pages:
1-6
Received:
16 December 2025
Accepted:
25 December 2025
Published:
19 January 2026
Abstract: The rapid increase in data transmission requirements in modern optical communication systems has made chromatic dispersion a major limiting factor in optical fiber links. At high bit rates, even moderate dispersion can cause significant temporal broadening of optical pulses, leading to intersymbol interference and degradation of system performance. Chromatic dispersion originates from the wavelength dependence of the refractive index of the fiber material and from the waveguiding properties of the fiber, causing different spectral components of an optical signal to propagate at different group velocities. In this study, chromatic dispersion in silica-based optical fibers is investigated through analytical modeling using realistic physical and system parameters suitable for numerical simulation. The analysis considers single-mode optical fibers operating in the second and third telecommunication windows, centered at wavelengths of 1.3 µm and 1.55 µm, respectively. Typical fiber lengths ranging from 10 km to 100 km are considered, along with optical sources having spectral widths between 0.1 nm and 2 nm, representative of laser diodes and light-emitting diodes used in practical systems. The refractive index dispersion of silica is modeled using the Sellmeier equation, allowing the calculation of the group refractive index and its wavelength derivatives. Based on these parameters, the group delay and temporal pulse broadening are analytically derived as functions of wavelength, fiber length, and source spectral width. For standard single-mode fibers, the chromatic dispersion coefficient is assumed to be approximately 0 ps/(nm·km) near 1.3 µm and about 17 ps/(nm·km) at 1.55 µm, in agreement with widely reported experimental data. Numerical simulations are performed by injecting Gaussian optical pulses with initial temporal widths on the order of 50 ps to 200 ps and peak powers normalized to unity. The temporal evolution of the pulses is analyzed after propagation over different fiber lengths. The results are expected to show minimal pulse broadening around 1.3 µm, while a noticeable temporal spreading is observed at 1.55 µm, increasing linearly with both fiber length and source spectral width. The quantitative analysis presented in this work provides a clear framework for simulating and evaluating chromatic dispersion effects in optical fiber transmission systems. The chosen numerical parameters enable direct implementation in simulation tools and offer practical insight into the trade-off between low attenuation and dispersion in high-capacity optical communication networks.
Abstract: The rapid increase in data transmission requirements in modern optical communication systems has made chromatic dispersion a major limiting factor in optical fiber links. At high bit rates, even moderate dispersion can cause significant temporal broadening of optical pulses, leading to intersymbol interference and degradation of system performance....
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Research Article
Optical and Structural Properties of TiO2 and CuAlSe2 Doped with Carbon Based Graphene for Photovoltaic Devices
Ladan Haruna Aminu*,
Ada Buba
Issue:
Volume 11, Issue 1, June 2026
Pages:
7-15
Received:
11 June 2025
Accepted:
4 February 2026
Published:
27 February 2026
DOI:
10.11648/j.jpmt.20261101.12
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Abstract: The preparation and characterization of copper aluminum diselenide (CuAlSe2) and Titanium dioxide (TiO2)-doped with carbon based graphene nanocomposite thin films were examined. The temperature, deposition time, and pH of the medium was varied by spin coating method. Samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive x-ray (EDX) and UV visible spectroscopy techniques for the structural, morphological, compositional features and photo-response for photovoltaic devices. The optical property revealed that CuAlSe2 films have energy band gaps range 2.22-5.80 eV and 2.10-2.14 eV at room and peak temperature. The XRD patterns of CuAlSe thin films showed peaks (101), (102), (006), (110), (108), and (116) corresponding to the formation of hexagonal phase of CuInSe2 and the particle size D 38.20 nm. XRD pattern of C: CuAlSe2 and TiO2 flakes were perfectly crystallized and the inter-planar spacing of 0.053 nm. FESEM analysis indicated smooth and uniform structures. The graphene-TiO2 displayed glistering surfaces due to less density of electronic trap states and improved absorption in the UV region. The resistivity of the samples were 1.95s/m and 12.93s/m for GO and GO-TiO2. The results indicated that the average electron mobility depends on the probability of the electrons in the conduction band and as the quasi-Fermi level approaches the CB, a higher current, power supply and lower resistivity level.
Abstract: The preparation and characterization of copper aluminum diselenide (CuAlSe2) and Titanium dioxide (TiO2)-doped with carbon based graphene nanocomposite thin films were examined. The temperature, deposition time, and pH of the medium was varied by spin coating method. Samples were characterized by X-ray diffraction (XRD), field emission scanning ele...
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