  Next-generation large segmented mirror telescopes are expected to perform
direct imaging and characterization of Earth-like rocky planets, which requires
contrast limits of $10^{-7}$ to $10^{-8}$ at wavelengths from I to J band. One
critical aspect affecting the raw on-sky contrast are polarization aberrations
arising from the reflection from the telescope's mirror surfaces and instrument
optics. We simulate the polarization aberrations and estimate their effect on
the achievable contrast for three next-generation ground-based large segmented
mirror telescopes. We performed ray-tracing in Zemax and computed the
polarization aberrations and Jones pupil maps using the polarization
ray-tracing algorithm. The impact of these aberrations on the contrast is
estimated by propagating the Jones pupil maps through a set of idealized
coronagraphs using hcipy, a physical optics-based simulation framework. The
optical modeling of the giant segmented mirror telescopes (GSMTs) shows that
polarization aberrations create significant leakage through a coronagraphic
system. The dominant aberration is retardance defocus, which originates from
the steep angles on the primary and secondary mirrors. The retardance defocus
limits the contrast to $10^{-5}$ to $10^{-4}$ at 1 $\lambda/D$ at visible
wavelengths, and $10^{-5}$ to $10^{-6}$ at infrared wavelengths. The
simulations also show that the coating plays a major role in determining the
strength of the aberrations. Polarization aberrations will need to be
considered during the design of high-contrast imaging instruments for the next
generation of extremely large telescopes. This can be achieved either through
compensation optics, robust coronagraphs, specialized coatings, calibration,
and data analysis approaches or by incorporating polarimetry with high-contrast
imaging to measure these effects.
