Microlocalization is a tool invented by Mikio Sato to study linear partial differential equations (as a part of his algebraic analysis program) not only locally in space but also locally in momentum variable. It is a purely algebraic theory that was also continued in parallel by analysts, like Hormander, giving the domain of microlocal analysis.
Sato’s theory of microlocalization was first described in the setting of D-modules:
It was then extended by M. Kashiwara and P. Schapira to a purely sheaf theoretical theory.
This theory of microlocalization of (ind)-sheaves was developped in the following works:
A good overview of the theory can by found at: