An electron microscope 10 is adapted to enable spectroscopic analysis of a sample 16. A parabolic mirror 18 has a central aperture 20 through which the electron beam can pass. The mirror 18 focuses laser illumination from a transverse optical path 24 onto the sample, and collects Raman and/or other scattered light, passing it back to an optical system 30. The mirror 18 is retractable (within the vacuum of the electron microscope) by a sliding arm assembly 22.