  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 corresponding LO estimate. Using a realistic luminosity
spectrum and performing a detector simulation with the SIMDET program, we find
that the Gamma(h -> gamma gamma)Br(h -> bb) decay can be measured with an
accuracy better than 2% after one year of photon collider running.
