An apparatus for collection, distribution, and analysis of cathodoluminescence (CL) and other light signals in an electron microscope is provided. The optical hub, utilizing a linear-translating fold-mirror and mounted to the electron microscope, is used to receive essentially collimated light collected from a collection-mirror and efficiently route the collected light to a plurality of light-analysis instruments. The linear-translating fold-mirror can provide fine positional alignment of the light signal, and in an aspect of the invention can be used to select or scan a portion of the collected light-pattern into an optical slit or aperture. In one aspect, the optical hub includes a light filter mechanism that can track the movement of the fold-mirror. In an aspect, the optical hub also controls the positioning of the collection-mirror in proximity to the specimen being analyzed.