  Simultaneous measurement of multiple qubits stored in hyperfine levels of
trapped 111Cd+ ions is realized with an intensified charge-coupled device (CCD)
imager. A general theory of fluorescence detection for hyperfine qubits is
presented and applied to experimental data. The use of an imager for photon
detection allows for multiple qubit state measurement with detection fidelities
of greater than 98%. Improvements in readout speed and fidelity are discussed
in the context of scalable quantum computation architectures.
