Taking partially coherent cosh-Gaussian(ChG) beams as an example of more general partially coherent beams,we have studied the spectral degree of coherence of partially coherent ChG beams in the far field.It is shown that,unlike Gaussian Schell-model(GSM) beams,in the strict sense there do not exist two partially coherent ChG beams which can generate far fields with the same spectral degree of coherence.However,under certain conditions it is possible to find two partially coherent ChG beams with the same spectral degree of coherence in the far field.
