POSITIVELY CHIRPED SIGNALS IN OPTICAL COMMUNICATION SYSTEMS

摘要

Disclosed is a telecommunications link having positively chirped optical signal pulses propagating in an optical waveguide fiber (52), at least a portion of which is characterized by a negative chromatic dispersion. An embodiment of the invention is a semiconductor laser source (46) in combination with negative dispersion optical waveguide fiber (52). The source (46) of the chirped signal pulses is selected to have predominantly adiabatic chirp as evidenced, in the case of a DFB laser (46), by a gain compression factor in the range of 4 x (10 power of -23)x(m power of 3) to 30x (10 power of -23) x(m power of 3). Eye closure penalty and bit error rate are maintained low for link lengths having cumulative dispersion parameter times distance product of the order of thousands of ps/nm. Optimum laser extinction ratio is found to be in the range of 5 to 10 dB, although extinction ratios as high as 20 dB are contemplated.