A scatterometric measurement system for measuring an object under test is disclosed. The scatterometric measurement system generates a beam of light from a light source sending the generated beam to illumination optics for transforming the beam and sending this transformed beam to a beam splitter. The beam splitter redirects the transformed beam to a first detector while deflecting the transformed light beam to the object under test which produces scattered light. Collection optics then receives this scattered light from the object under test and processes and sends the scattered light to a second detector through the beam splitter. The second detector generates a signal based on this processed scattered light and sends this result to a computation unit that calculates using the second detectors signal a desired output according to an algorithm for a given measurement for the object under test.
