o:18314 Mоделовање полупроводничких оптичких појачавача за примене у оптичким приступним мрежама докторска дисертација Modeling of semiconductor optical amplifiers for optical access networks : doctoral dissertation sr Predmet ove disertacije jeste razvoj detaljnih i efikasnih numeričkih i analitičkih modela poluprovodničkih optičkih pojačivača, za primrnu u pristupnim optičkim mrežeme... The object of the dissertation is the development of various detailed and efficient numerical and analytical models of semiconductor optical amplifiers, employed in access optical networks. Starting from the optical properties of active regions based on the bulk semiconductor and the multiple quantum wells, the theoretical model of the two most commonly used amplier types traveling-wave and reective, is developed, such that the ampliers are optimized to be polarization insensitive. The models are based on a system of integro-dierential equations, written with respect to carrier densities, spectral photon densities of the signals and noise, and signals' phases for both propagation directions. First o, a wideband steady-state amplier model is developed, together with the accompanying numerical algorithm, further used for a detailed amplier analysis. It has been shown that the reective amplier exhibits pronounced resonances and antiresonances in the spectrum of the output amplied spontaneous emission noise. The transmission gain of the reective ampliers proves to be higher in comparison to the traveling-wave ones. Results show that spectrally dependent connement factor and refractive index variation signicantly inuence the transmission gain. Relying on a set of appropriately chosen approximations, a new, semi-analytical model is developed, together with the algorithm for its implementation. Semianalytical model provides reliable results within the time that is up to two orders of magnitude shorter in comparison with the wideband steady-state model, which makes it an attractive choice for software solutions intended for modeling of complex optical communication systems. Dynamic analysis starts with the large signal numerical model, implemented using the ½up-wind\ scheme for equation solving. It has been shown that both amplier types can be successfully used in electro-optic signal (re)modulation. Dynamic characteristics are further studied using a detailed small-signal model with the current modeled as a traveling microwave. Results reveal that reective ampliers exhibit two maxima in −3dB bandwidth dependence on input optical power, which is not the case with their traveling-wave counterparts. Finally, analytical formulae for −3dB bandwidth of both amplier types are developed, for a commonly chosen transparency operating regime, which show excellent qualitative agreement with the results obtained using the numerical model. Based on the obtained results, guidelines are provided for the choice of operating regime, geometrical and structural amplier parameters, for increasing the transmission gain and the modulation bandwidth. Фотоника и квантна електроника-Оптоелектроника и фотонсске комуникације / Photonics and quantum electronics-Optoelectronics and photonics communication Datum odbrane: 15. 6. 2018. 3dB propusni opseg, elektro-optička (re)modulacija, modulacioni odziv, numeričko modelovanje 3dB bandwidth, access optical networks, amplied spontaneous emissionnoise, electro-optical (re)modulation, modulation response, numerical modeling,semiconductor optical ampliers, transmission gain yes 50432783 91552101 6019 91552100 50432783 2018-09-27T18:29:10.053Z 45 no 46 mentor Angelina R., 1988- Totović 2018 63 mentor Dejan, 1964- Gvozdić 2018 63 član komisije Jasna, 1978- Crnjanski 2018 63 član komisije Zlatan, 1965- Šoškić 2018 63 član komisije Nataša, 1969- Nešković 2018 63 član komisije Marko. Krstić 2018 174 листа 15380998 http://phaidrabg.bg.ac.rs/o:18314 no yes 3 2018-09-27T18:29:10.320Z 70 11 1067197 1067243 1067262 1067263 3dB propusni opseg, elektro-optička (re)modulacija, modulacioni odziv, numeričko modelovanje 3dB bandwidth, access optical networks, amplied spontaneous emissionnoise, electro-optical (re)modulation, modulation response, numerical modeling,semiconductor optical ampliers, transmission gain 621.375:621.382(043.3) 1738 11A04 2018