  We show a systematic construction for implementing general measurements on a
single qubit, including both strong (or projection) and weak measurements. We
mainly focus on linear optical qubits. The present approach is composed of
simple and feasible elements, i.e., beam splitters, wave plates, and polarizing
beam splitters. We show how the parameters characterizing the measurement
operators are controlled by the linear optical elements. We also propose a
method for the implementation of general measurements in solid-state qubits.
