  We study possible anomalous top-quark couplings generated by SU(2) x U(1)
gauge invariant dimension-6 effective operators, using the final b-quark
momentum distribution in gamma gamma -> tt -> bX. Taking into account
non-standard tt gamma, tbW and gamma gamma H couplings, we perform an
optimal-observable analysis in order to estimate the precision for the
determination of all relevant non-standard couplings.
