  When implementing quantum tasks practically, the imperfection of devices
should take into account. Among all, One of the significant but unsolved
problems is the dark count effect caused by single photon detectors. In this
paper, we consider such an issue and define a new optimality for measurements,
reflecting the robustness in dark count effects with practical detectors. Also,
an optimization scheme for general measurements is provided. This research
could be the first one trying to handle dark count effects based on optimizing
the choice of measurements, and we believe that the problem can be reduced by
the scheme.
