  We study regenerated high-energy emission from the gamma-ray burst (GRB)
afterglows, and compare its flux with the direct component from the same
afterglow. When the intrinsic emission spectrum extends to TeV region, these
very high-energy photons are significantly absorbed by the cosmic infrared
background (CIB) radiation field, creating electron/positron pairs; since these
pairs are highly energetic, they can scatter the cosmic microwave background
radiation up to GeV energies, which may change the intrinsic afterglow light
curve in the GeV region. Using the theoretical modeling given in literature and
the reasonable choice of relevant parameters, we calculate the expected light
curve due to the regeneration mechanism. As the result, we find that the
regenerated emission could only slightly change the original light curve, even
if we take a rather large value for the CIB density, independently of the
density profile of surrounding medium, i.e., constant or wind-like profile.
This ensures us the reliable estimation of the intrinsic GRB parameters when
the high-energy observation is accessible, regardless of a large amount of
uncertainty concerning the CIB density as well as extragalactic magnetic field
strength.
