  Measuring the Gamma(h -> gamma gamma)Br(h -> bb) decay at the photon collider
at TESLA is studied for a Standard Model Higgs boson of mass m_h = 120 GeV. The
main background due to the process gamma gamma -> QQ(g), where Q = b,c, is
estimated using the NLO QCD program (G. Jikia); the results obtained are
compared with the LO estimate. Using a realistic luminosity spectrum and
performing a detector simulation, we find that Gamma(h -> gamma gamma)Br(h ->
bb) can be measured with an accuracy better than 2% after one year of photon
collider running.
