Generation, propagation and detection of multi-bound solitons for optical communications

Optical fibres can transmit terabit per second of information over thousands of kilometres. Although impressive, this performance is quickly being used up by new internet applications. Thus there is a constant need for innovation in optical communications systems. One such innovation is multi-bound solitons, which are groups of pulses that maintain their spacing over extremely long distances, so do not interfere with one another. This thesis provides detailed studies of the generation, propagation and detection of bound solitons for telecommunications applications. For generation, nonlinear actively-mode-locked fibre lasers are studied in detail, using analysis, numerical simulations and experiments. Their stability under a wide variety of operating conditions is investigated. Stable bound solitons can be generated when the laser’s power is increased sufficiently. Excellent agreement between the simulated results and the experimental measurements for pulse width, pulse spectrum and RF spectrum is obtained. These bound solitons were then propagated through standard single-mode transmission fibre. Experimental measurements show that the solitons remain bound in a single span of fibre. Numerical simulations illustrate the dynamics of the solitons at various powers. Again, excellent agreement is found between experimental and numerical results. A novel technique for the detection and analysis of bound solitons is proposed. This uses bi-spectral analysis. A method of implementing bispectral analysis using four-wave mixing in optical fibres is investigated.