Title :
Performance limitations of amplified coherent optical transmission systems due to interfering echoes
Author :
Walker, G.R. ; Steele, R.C. ; Walker, N.G.
Author_Institution :
British Telecom Res. Lab., Ipswich, UK
fDate :
5/1/1990 12:00:00 AM
Abstract :
Interfering echoes produced in semiconductor amplifier cascades are known to cause bit error rate (BER) degradations in optical transmission systems. An experimental investigation of the effect of interfering echoes in a coherent differential phase-shift keying (DPSK) system is described and results in good agreement with theoretical predictions are reported. It is concluded that interfering echoes limit the minimum allowable inter-amplifier attenuation, which in turn severely limits the number of semiconductor laser amplifiers that can be cascaded without optical isolation.<>
Keywords :
echo; light coherence; light interference; optical links; optical losses; optical modulation; phase shift keying; semiconductor junction lasers; amplified coherent optical transmission systems; bit error rate; cascaded; coherent differential phase-shift keying; degradations; interfering echoes; minimum allowable inter-amplifier attenuation; semiconductor amplifier cascades; semiconductor laser amplifiers; Bit error rate; Degradation; Differential phase shift keying; Differential quadrature phase shift keying; Laser theory; Optical attenuators; Quantum cascade lasers; Semiconductor lasers; Semiconductor optical amplifiers; Stimulated emission;
Journal_Title :
Photonics Technology Letters, IEEE
