  Gravitational microlensing is one of the methods to detect exoplanets;
planets outside our solar system. Here we focus on theoretical modeling of
three lens systems and in particular circumbinary systems. Circumbinary systems
include two stars and a planet and are estimated to make up a sizable portion
of all exoplanets. Extending a method developed for binary lenses to the three
lens case, we explore the parameter space of circumbinary systems producing
exact magnification maps and light curves.
