System and method for measuring angular luminescence in a charged particle microscope

Cathodoluminescence performed in the scanning electron microscope brings the advantage of localized excitation of individual microscopic structures. When luminescent structures are characterized, the intensity, wavelength, polarization and angular emission of the luminescence are all of interest. The invention provides an apparatus for determining the angular distribution of the radiated light, and in particular provides the user with rotational symmetry which is essential for the principle of measurement. This is compatible with additional polarization and spectral bandpass filtering methods used to characterize the luminescence and understand the specimen.