Moving cavity solitons in a cavity soliton laser

Cavity solitons (CSs) are bright intensity peaks over a dark homogeneous background. They arise in the coherent field transmitted by nonlinear optical resonators, and are generated through diffraction-mediated light-matter interaction which leads to field self-localization within the cavity. CSs have been experimentally demonstrated in broad area, driven vertical cavity surface emitting laser (VCSELs) below and above threshold. In a laser with a saturable absorber (LSA) it is possible to achieve the optimal condition where CSs coexist with a dark state of pure spontaneous emission corresponding to a laser below threshold. Under this condition the contrast between the CSs and the homogeneous background is maximum. On the other hand, since such a device is able to generate CSs without an external holding beam, it is the realization of a Cavity Soliton Laser (CSL).