Propagation of highly chirped pulses in fiber-optic communications systems

Abstract

Abstract-The propagation of strongly chirped pulses in an amplified fiber-optic communications system is experimentally investigated. Spectral narrowing of the pulses is observed. The narrowing is attributed to interplay between the initial chirp and the nonlinearity in the transmission line. Four-wave mixing (FWM) between wavelength channels is found to be similar to that for unchirped nonreturn-to-zero (NRZ) pulses. Low error rate transmission over 720 km is achieved using these chirped pulses, which are generated by a transmitter based on a modelocked fiber laser.Index Terms-Mode locked lasers, nonlinear optics, optical fiber communication, optical fiber dispersion, optical fiber lasers.

Comparison between Finite-Difference Time-Domain Method and Experimental Results for Femtosecond Laser Pulse Propagation

“…The DFWM is robust for chirping. (Cundiff et al, 1999), (Geraghty et al, 1998) www.intechopen.com (Nakamura et al, 2005b) When the two pulses meet at the end of the fiber T d = 80 fs, the trailing edge of the signal pulse mainly interacts with the leading edge of the fundamental pulse and the chirped pulses gradually become overlapping at the places where the pulses are temporally broadened; therefore, the interaction length is long. As a result, the four-wave mixing effect is enhanced and a larger parabolic phase curve of the anti-Stokes light in the spectral phase is observed.…”

Optimal dispersion precompensation by pulse chirping

“…[1][2][3][4] Prechirping accomplishes various objectives including suppression of four-wave mixing, 3,4 the lowering of pulse-width fluctuations, 5 spectral compression, 6,7 and the generation of transformlimited output pulses. 4 In dispersion-managed soliton systems a chirped pulse can experience pulse width and phase fluctuations but, with the correct prechirp, can be made to return to its exact initial conditions after a given propagation distance.…”

Significance of prechirping on long-haul path-averaged soliton impulse in re-circulating loop at 10 and 20 Gb/s with TOD

“…It has been shown in Fig. 1 that there is initial pulse compression due to fiber nonlinearity on the pulse propagation for fundamental soliton (N also been reported in [18]. In case of a fundamental soliton (N ¼ 1), the optimum value of pulse width (FWHM) is obtained at zero chirp.…”