Analysis of Angular-Differential Post-Processing Algorithms for Exoplanet Direct Detection with a Photonic Lantern Nuller

Exoplanet research is essential for understanding planetary formation and potential life beyond our solar system. Various methods have contributed to the detection and characterization of exoplanets, leading to approximately 5,500 discoveries. Direct imaging, a method that has been technologically limited until recently, involves capturing images of exoplanetary systems while minimizing the light from the host star. This is mainly done using an instrument called Coronagraph which allows us to characterize the planet's atmospheres and features to a high degree. The Photonic Lantern Nuller (PLN) is a novel instrument for direct imaging of closely orbiting exoplanets. Modern coronagraphs operate on the principles that the planet's signal remains rotationally invariant in the sky and there is minimal overlap between the stellar and planet signals. This enables imaging of planets at various angles by setting the telescope's rotator to follow the pupil instead of the field. However, PLN images are a one-dimensional collection of four points without rotational invariance and contain more stellar noise. This requires adapting the Angular Differential Imaging (ADI) post processing technique, which typically subtracts stellar noise by derotating frames, for use with PLN data. We propose a reformulation of ADI to work with simulated PLN data and develop a method to extract spatial parameters of exoplanets from 1D PLN images.