You might want to read a bit about Hesychasm and the uncreated light - these kind of experiences have been part and parcel of Christian mysticism since before the first millennia. I think it is interesting to know about these things for a comparative perspective.
It is interesting to note though, that especially in later times, many of these practices took on eastern language i.e uncreated, guarding the mind, true self ect. http://orthodoxwiki.org/Hesychasmhttp://en.wikipedia.org/wiki/Theoria
But just because they experience concentration, lights, rapture ect. doesn't necessarily make it genuine jhana, though it all seems to be based on the same principles - seclusion, refraining from immorality, deep focus on one object or sound.
"If beings knew, as I know, the results of giving & sharing, they would not eat without having given, nor would the stain of miserliness overcome their minds. Even if it were their last bite, their last mouthful, they would not eat without having shared."