Development of misalignment conditions of a rotational shearing interferometer to detect extra-solar planets

Abstract

We are interested in detecting planets around nearby stars by direct methods. Previously, we developed the radiometric and imaging conditions for detection of extra-solar planets. With star to planet irradiance factor of 10 5 , it appears that the interferometric method is the most likely to produce adequate signal. A rotational shearing interferometer (RSI) may be used to cancel the infrared radiation of the host star, allowing the detection of the planet. We have established the conditions for star-radiation cancellation with an RSI. Among these conditions, we have that the star must be on the optical axis, and that the phase difference between the interferometer arms must be π. Nevertheless, the ideal conditions are almost impossible to achieve. Therefore, we have analyzed the caused effect when we consider that the star is not on the optical axis, and an arbitrary phase difference is included. In this work, we extend the study considering the interferometer misalignments.