  We present modeled detection limits of the Gemini Planet Imager (GPI) and the
Wide-Field Infrared Space Telescope (WFIRST) to an optical and infrared laser
which could be used by an extraterrestrial civilization to signal their
presence. GPI and WFIRST could utilize a coronagraph to search for
extraterrestrial intelligence (SETI) in the present and future. We use archival
data for GPI stars and simulated WFIRST observations to find the detectable
flux ratio of a laser signal to residual scattered starlight around the target
star. This flux ratio is then converted to detectable power as a function of
distance from the parent star. For GPI, we assume a monochromatic laser
wavelength of 1.55 $\mu$m, and a wavelength of 575 nm for WFIRST. We assume the
lasers are projected through a 10-m aperture, and that the intensity of the
laser beam follows a Gaussian profile. Our analysis is performed on 6 stars
with spectral types later than F within 20 pc (with an emphasis on solar
analogs at different distances). The most notable result is the detection limit
for $\tau$ Ceti, a G5V star with four known exoplanets, two of those within the
habitable zone (HZ). The result shows that a 24 kW laser is detectable from
$\tau$ Ceti from outside of the HZ with GPI and a 7.3 W laser is detectable
from within $\tau$ Ceti's HZ by WFIRST.
