1. A measurement apparatus for electromagnetic waves, comprising: a light transmissive optical pathway defining at least one signal path for an input light wave; at least one intensity measurement unit disposed along the signal path, said intensity measurement unit being responsive to an intensity level of the input light wave along the signal path; at least one selectively operated light processing element along the signal path up to said intensity measurement unit, the selectively operated light processing element being controllably operable for at least one of filtering and transforming at least one polarization attribute of at least a portion of the input light wave incident on the intensity measurement unit; a data processor coupled to the selectively operated light processing element and to the intensity measurement unit, the data processor controlling the selectively operated light processing element and encoding a value of the polarization related level of the input light wave, for deriving at least one polarization attribute of the input wave.