  Possible anomalous top-quark couplings induced by SU(2) x U(1)
gauge-invariant dimension-6 effective operators were studied in the process of
t t-bar productions and decays at polarized gamma gamma colliders. Two
CP-violating asymmetries, a linear-polarization asymmetry and a
circular-polarization asymmetry, were computed including both non-standard [t
t-bar gamma] and [gamma gamma H] couplings. An optimal-observable analysis for
the process gamma gamma --> t t-bar --> l^{+-} ... was performed in order to
estimate the precision for determination of all relevant non-standard
couplings, including the anomalous tbW coupling.
