  A mathematical extension of the weak value formalism to the simultaneous
measurement of multiple parameters is presented in the context of an optical
focused vector beam scatterometry experiment. In this example, preselection and
postselection are achieved via spatially-varying polarization control, which
can be tailored to optimize the sensitivity to parameter variations. Initial
experiments for the two-parameter case demonstrate that this method can be used
to measure physical parameters with resolutions at least 1000 times smaller
than the wavelength of illumination.
