Studying wave optics in the light curve of exoplanet microlensing

We study the wave optics features of gravitational microlensing by a binary lens composed of a planet and a parent star. In this system, the source star near the caustic line produces a pair of images in which they can play the role of secondary sources for the observer. This optical system is similar to the Young double-slit experiment. The coherent wave fronts from a source on the lens plane can form diffraction pattern on the observer plane. This diffraction pattern has two modes from the close- and wide-pair images. From the observational point of view, we study the possibility of detecting this effect through the Square Kilometer Array (SKA) project in the resonance and high magnification channels of binary lensing. While the red giant sources do not seem satisfy the spatial coherency condition, during the caustic crossing, a small part of source traversing the caustic line can produce coherent pair images. Observations of wave optics effect in the longer wavelengths accompanied by optical observations of a microlensing event provide extra information from the parameter space of the planet. These observations can provide a new basis for study of exoplanets.