Postcolonialism refers simply to the socioeconomic situation that countries find themselves in after shedding the political status of a colony. French postcolonialism and the situation of la francophonie are of particular interest to me in my research, and they are especially interesting because the so-called field of "postcolonialism" is not nearly as significant in France as it is in the U.S. To cite Emily Apter: "there is really no commensurate intellectual movement [to postcolonialism] on the European continent."
Why might this be? I will offer two reasons, that could be expanded, revised, or challenged. But as I see it, [ALERT: unproven assertion] the field of postcolonialism, like most post- fields, tends towards radicalism, which tends to make more headway in U.S. academia than European academia. And by radicalism, I mean not only extreme left-wing theorizing but also at times academic nincompoopery. More on that in a later post, but as preliminary reading, try out Postcolonialism: A Very Short Introduction or Orientalism and see if you don't agree with me.
The second reason is the still uneasy relationship France has with some of its former colonies. It has tried to develop/maintain amicable relationships with francophone countries of the African continent, but it is awkward to move from colonizer/colonized to equal economic partners. In reality, some African countries, though independent, are still highly dependent on France and thus not autonomous.