  In our Letter we proposed a scheme for nondeterministic quantum nondemolition
(QND) measurement of the polarization of a single photon--a photonic
qubit--using linear optics and photodetection. The scheme works with nonunit
probability, but success is heralded by the detection of a single photon in the
meter output. We provided an experimental demonstration of this scheme and
introduced three universally applicable fidelity measures--the measurement
fidelity F_M, the quantum state preparation fidelity F_QSP, and the QND
fidelity F_QND--to quantify its performance. The claim of Kok and Munro in
their Comment [quant-ph/0406120] is that one of our fidelity measures F_M is
not appropriate because it relies on coincidence measurements. We show why this
claim is wrong from both a fundamental and an operational perspective.
