Lorentz and CPT violation in the photon sector with the operators of arbitrary mass dimension has been proposed in the context of Standard-Model Extension. The CPT-odd subset of this enlarged model is investigated from a quantum-field theoretical poi
nt of view. The generic forms of dispersion relations, polarization vectors and the propagators are obtained for this special subset. Particularly, the general vacuum-orthogonal model is analyzed and it is demonstrated that the vacuum orthogonal model remains vacuum orthogonal at all orders. Although the model has birefringent solutions, they are shown to be spurious. Furthermore, the relevant polarization vectors are shown to be conventional. Leading order model is explicitly analyzed and it is demonstrated that there exists a nontrivial coefficient space satisfying above properties.
