I'm not sure about this, but I don't think they met. For one thing, Field spent much of his life in Russia, so there would have been little opportunity for them to meet. I think he moved to Russia around the time Chopin was born. He did return to Europe a few times (I think), but I doubt they would have been in the same city at the same time. Even though they probably didn't meet, Field was a big influence on Chopin. You can hear this in many of Chopin's early nocturnes.