The paper presents a technique for applying a wavelet analysis (continuous and discrete wavelet transforms) to analyze the elemental composition of nanostructures in order to identify the chemical composition. The experimental data were obtained by means of a scanning electron microscope. The acquisition, processing and study of spectra were carried out using the author’s software product “labpraktikum_osnov_wavelet”.

In this paper, we are going to exhibit the system performance using the single, double and three-electrode quantum-dot semiconductor optical amplifier as an intensity modulator (3E-QD-SOA-IM) of the adaptively modulated optical orthogonal frequency division multiplexing (AMOOFDM) signals in the intensity-modulation direct-detection passive optical network (IMDD-PON) systems. Moreover, to compare the bit-rate versus transmission distance of the proposed fiber link model when using both configurations multi-electrode semiconductor optical amplifier intensity-modulator (ME-SOA-IM) and multi-electrode quantum-dot semiconductor optical amplifier intensity-modulator (ME-QD-SOA-IM), to study the improvement of the transmission capacity, distance reach and power efficiency when applying the proposed configurations for optical access networks for distances ranging from 20 km up to 120 km. The three-electrode configuration solved the nonlinearity of the two-electrode configuration and offered a considerably wider range of optimum operating conditions to achieve up to 35 Gbps. Furthermore, the 3E-QD-SOA-IM showed a better performance over the 3E-SOA-IM over all the 120 km, and a 5 Gbps enhancement in the bitrate with a 20 dB less optical input power at 20 km.

The article discusses the prospects of modernization of the author’s software «labpraktikum_osnov_wavelet» for studying and analyzing the parameters and characteristics of a semiconductor optical amplifier (SOA) by expanding the list of wavelet analysis types in order to select the most informative type of wavelet analysis and wavelet function to interpret the results.

Access networks are under constant development looking for customer’s satisfaction by enhancing the internet service speed and the cost of the service. Moreover, trying to serve as many residential units as possible by extending the distance reach of the access network to cover a part of a big city or to reach a rural area in a range up to 60 km. Nowaday’s networks still experience limitations in services, coverage area, and still pricey for average customers. However, a significant percentage of these networks still using the terrestrial radio wave telecommunications to distribute the service inside or between city blocks, while others use the fiber to the home (FTTH). In this article, we are comparing the performance of the currently operated access networks to the adaptively modulated optical orthogonal frequency multiplexing (AMOOFDM) based access networks, according to the bit-rate, and the distance reach of these networks; highlighting the advantages of the AMOOFDM system using some types of the semiconductor optical amplifier (SOA) as an intensity modulator.