An optical transmission system using Fiber Bragg Grating (FBG) and Erbium Doped Fiber Amplifier (EDFA) with new proposed model has been analyzed to overcome chromatic dispersion and attenuation phenomena. To evaluate the transmission system performance of the received signals, a simple model of one channel transmission has been developed in the first step. Also, optical fiber length and attenuation coefficient parameters have been investigated in detail to deal with the optimized corresponding parameter values. Results show that the performance of the optimized design parameters is very efficient in terms of output power (dBm), noise figure (dB), gain (dB), and Q-Factor. The model of one channel developed previously has been adapted to a complex model of four optical channels multiplexing with different wavelengths. FBG and EDFA have been also added to WDM technology system to enhance the chromatic dispersion and the signal attenuation. Results show that the new model is more efficient in terms of Q-Factor and eye diagrams.

A novel optimized apodization of Fiber Bragg Grating Sensor (FBGS) for quasi-distributed strain sensing applications is developed and introduced in this paper. The main objective of the proposed optimization is to obtain a reflectivity level higher than 90% and a side lobe level around −40 dB, which is suitable for use in quasi-distributed strain sensing application. For this purpose, different design parameters as apodization profile, grating length, and refractive index have been investigated to enhance and optimize the FBGS design. The performance of the proposed apodization has then been compared in terms of reflectivity, side lobe level (SLL), and full width at half maximum (FWHM) with apodization profiles proposed by other authors. The optimized sensor is integrated on quasi-distributed sensing system of 8 sensors demonstrating high reliability. Wide strain sensitivity range for each channel has also been achieved in the quasi-distributed system. Results prove the efficiency of the proposed optimization which can be further implemented for any quasi-distributed sensing application.

This paper presents a detailed study of N-channels Wavelength Division Multiplexing (WDM) Optical transmission system using Radio over Fiber (RoF) technology. The study was applied to optical long-haul networks to overcome the nonlinearity effects, chromatic dispersion, and signal loss. For this purpose, Fiber Bragg Grating (FBG) has been implemented in 4-channels, 8-channels, and 16 channels WDM transmission system network at 10 Gb/s to compensate the dispersion and the nonlinear distortion. The use of erbium-doped fiber amplifiers (EDFA) has been also investigated to improve the quality of the transmission system. In Digital RoF, the impact analysis of modulation types such as Differential Phase-Shift Keying (DPSK) and Quadrature Amplitude Modulation (QAM) is also introduced. Constellation diagrams, received optical power, types of modulation, fiber dispersion, channel spacing variation, and laser power were considered to validate the study with the existing studies. All results achieve good reliability performance and prove the efficiency of the presented model.

Dense wavelength division multiplexing (DWDM) is considered as a mainstream solution for 5G optical transmission networks to confront increasing bandwidth demand. In such a dense multiwavelength system, the four wave mixing (FWM) non-linear effect limits the achievable transmission distance and channel capacity. For this reason, and to the best of our knowledge, a new unequal channel allocation (UCA) has been introduced in this paper based on new closed-form equations to reduce the FWM crosstalk in the DWDM optical long-haul network. The proposed channel allocation has been investigated based on several design parameters that affect FWM nonlinear crosstalk, such as total transmission distance, channel frequency spacing, the number of WDM channels, and the input power per channel. The suggested technique has further been compared with a previous model proposed by other authors to prove the effectiveness of this work. The simulation results have been examined and validated by analysing the optical spectrum analyser and the power of the FWM spectral products. Results demonstrate the reliability and the efficiency of the developed method.