Two-dimensional computer simulations are carried out to quantify the quality of
apodized square aperture (ASA) in terms of the diffraction limited resolution and the
efficiency of detection of faint companions. The study involve the quality of the
point spread function (psf), and the modulation transfer function (MTF) of a
reference star. Annular apodized square aperture (AASA) is also considered in this
study. The results are then compared with the classical circular aperture.
ASA shows high contrast which increases the possibility of detection of faint
companions and AASA demonstrates significant high frequency components which
leads to high resolution.