  We propose a scheme to generate entanglement between a single-photon qubit in
the polarization basis and a coherent state of light. The required resources
are a superposition of coherent states, a polarization entangled photon pair,
beam splitters, the displacement operation, and four photodetectors. Even when
realistic detectors with a limited efficiency are used, an arbitrarily high
fidelity can be obtained by adjusting a beam-splitter ratio and the
displacement amplitude at the price of reducing the success probability. Our
analysis shows that high fidelities may be obtained using on-off detectors with
low efficiencies and available resource states under current technology.
