  We compare three different types of optical qubits for information transfer
via quantum teleportation and direction transmission under photon losses. The
three types of qubits are (1) qubits using the vacuum and the single-photon
(VSP) states, (2) single-photon qubits using polarization degrees of freedom,
i.e., polarized single-photon (PSP) qubits, and (3) coherent-state qubits that
use two coherent states with opposite phases as the qubit basis. Our analysis
shows that the teleportation scheme outperforms the direct transmission for
most of cases as far as fidelities are concerned. Overall, VSP qubits are found
to be the most efficient for both the direct transmission and teleportation
under photon loss effects. The coherent-state qubits are more robust than PSP
qubits either when their amplitudes are small as $|\alpha| \lesssim 1.22$ or
when photon loss effects are strong. Our results would provide useful and
timely information for the development of practical optical quantum information
processing particularly in the context of hybrid architectures.
