Simple nonstationary generalization of Gaussian Shell-model beams
  Model of partially coherent pulses, based on the concept of "hidden coherence", introduced recently by Picozzi and Haelterman in framework of parametric wave mixing, is presented. The nonuiform and nonstationary phase shift, while completely deterministic, results in the beam properties, which are typical for partially coherent light - low contrast of interference effects, increase of spectral width and so on - i. e. light becomes effectively non-coherent. The proposed model is studied in framework of coherent mode decomposition, its main properties and limitations of the model are discussed. 
Mikalai Karelin