  We study the effect of diffuse intracluster light on the critical surface
mass density estimated from photometric redshifts of lensing source galaxies,
and the resulting bias in a weak lensing measurement of galaxy cluster mass.
Under conservative assumptions, we find the bias to be negligible for imaging
surveys like the Dark Energy Survey (DES) with a recommended scale cut of >=200
kpc distance from cluster centers. For significantly deeper source catalogs
from present and future surveys like the Large Synoptic Survey Telescope (LSST)
program, more conservative scale and source magnitude cuts or a correction of
the effect may be necessary to achieve per-cent level lensing measurement
accuracy, especially at the massive end of the cluster population.
