In a dynamic WDM-OXC, due to the various available paths for an incoming signal, there exits a special kind of samewavelength
crosstalk, termed same-source crosstalk. Its impact on the system is more severe than that of other kinds of
crosstalk under the worst case. This paper also points out that, by introducing light path differences between different
channel, one can distinctly reduce the impact of the same-source crosstalk with simple and minimum hardware cost.