Propagation dynamics of multi-Gaussian Schell model beams in strongly nonlocal nonlinear media.

The analytical propagation formulae of a single multi-Gaussian Schell model (MGSM) beam and two MGSM beams in strongly nonlocal nonlinear media (SNNM) are derived, and the optical breather characteristics of a single MGSM beam and two MGSM beams in SNNM are studied, respectively. It is found that a MGSM soliton is never formed because of the self-shaping feature of MGSM beams, but a MGSM breather can be formed. Furthermore, for a MGSM breather, the Gaussian-like profile and the flat-top profile alternate periodically during propagation. On the other hand, even if the separation distance is large enough, two MGSM breathers can be combined into a single breather due to nonlinearity when the threshold critical power arrives. Furthermore, the relationship between the threshold critical power and the MGSM beam parameters is also investigated.