In the simplest model, system performance is degraded by chirping because the line is broadened, and intersymbol interference is increased. System degradation increases dramatically beyond 1 Gbit/ sec, because the shift in wavelength occurs principally at the pulse edges.1 In this model of chirping the wavelength shifts are assumed to be the same from pulse to pulse. However, measurements described here show that this is not the case; frequency chirping varies from pulse to pulse, and this fluctuation is defined as chirping noise. The latter is analogous to the well-known2 mode partition noise (MPN) of multilongitudinal-mode lasers.
© 1985 Optical Society of AmericaPDF Article