tailieunhanh - Influence of the frequency-chirp gaussian pulse on the pulse broadening in the dispersive fibers

In this paper, the expression of the signal optical pulse with the frequency-chirp propagated through the dispersive fiber is derived. This expression described the broadening of the pulse in propagating process (broadening factor), which depends on the frequence chirp and dispersive parameters. The influence of those parameters on the pulse broadening is simulated and discussed. | Communications in Physics, Vol. 23, No. 1 (2013), pp. 85-89 INFLUENCE OF THE FREQUENCY-CHIRP GAUSSIAN PULSE ON THE PULSE BROADENING IN THE DISPERSIVE FIBERS BUI XUAN KIEN Electric Power University TRAN HAI HUNG Nghe An Pedagogical College TRINH DINH CHIEN University of Science, Vietnam National University, Hanoi, Vietnam Abstract. A signal optical pulse propagating in the fiber is affected by many factors, one of the most important among them is dispersion. Under the dispersive influence, the optical pulse is reshaped, particulally, its duration is changed. Especially, the pulse duration change of the optical short pulse with the frequency-chirp is unregular. It influences to the propagating distance in the fiber optic network. In this paper, the expression of the signal optical pulse with the frequency-chirp propagated through the dispersive fiber is derived. This expression described the broadening of the pulse in propagating process (broadening factor), which depends on the frequence chirp and dispersive parameters. The influence of those parameters on the pulse broadening is simulated and discussed. I. INTRODUCTION As well known, in the optical communication, the most interesting problems are the pulse sharping and propagating distance. It is fact that the signal optical pulse propagating in the dispersive fiber is always affected by the nonlinear effects as disspersion, self-phase modulation and cross-phase modulation,.[1-5], which broadens (or narrowes) the pulse, expecially, the pulse with frequency-chirp and consequently, reduces the bit rate. Up to now, the dispersive questions are interested in many works [2, 3], but till not paied attentions on the influence of the pulse with the frequency-chirp on the propagating distance in the fibers. We present the expressions of the optical pulse propagated through the optical fiber and of the broadening factor in Sec. 2. The influence of the chirp and dispersive parameters on the broadening is simulated and .