Abstract

By recirculating soliton pulses many times around a closed 42-km fiber loop with loss exactly compensated by Raman gain, we have successfully demonstrated soliton transmission, without electronic regeneration, over distances of up to 6000 km.¹,² (For experimental details, see Ref. ¹ or ².) By using a slight excess of Raman gain, we have also been able to demonstrate adiabatic compression of the originally 55-ps soliton pulses by as much as 4X, with nearly perfect preservation of the ΔtΔf product (0.315) expected for sech shaped pulses. We have also been able to study interaction between closely spaced soliton pairs over thousands of kilometers: In addition to the expected phase-dependent, attractive/repulsive interaction from direct overlap of the pulse tails, we also see a small but significant long range interaction resulting from dispersive wave radiation. Finally, we have also shown that solitons are resistant to broadening from fiber birefringence, but that such polarization dispersion is the source of significant amounts of dispersive radiation. These studies have obvious implications for the development of an all-optical, long distance transmission system.

© 1989 Optical Society of America