  Search for new-physics through possible anomalous t tbar gamma, tbW and gamma
gamma H couplings which are generated by SU(2) X U(1) gauge-invariant
dimension-6 effective operators is discussed, using energy and angular
distributions of final charged-lepton/ b-quark in gamma gamma -> t tbar -> l X
/ bX for various beam polarizations. Optimal beam polarizations that minimize
uncertainty in determination of those non-standard couplings are found
performing an optimal-observable analysis.
