  A barrier to realizing the potential of molecules for quantum information
science applications is a lack of high-fidelity, single-molecule imaging
techniques. Here, we present and theoretically analyze a general scheme for
dispersive imaging of electronic ground-state molecules. Our technique relies
on the intrinsic anisotropy of excited molecular rotational states to generate
optical birefringence, which can be detected through polarization rotation of
an off-resonant probe laser beam. Using \narb and \rbcs as examples, we
construct a formalism for choosing the molecular state to be imaged and the
excited electronic states involved in off-resonant coupling. Our proposal
establishes the relevant parameters for achieving degree-level polarization
rotations for bulk molecular gases, thus enabling high-fidelity nondestructive
imaging. We additionally outline requirements for the high-fidelity imaging of
individually trapped molecules.
