This is done using an integrated cathodoluminescence and scanning electron microscope. Under electron irradiation, it emits strong blue cathodoluminescence. For example, scanning electron microscope (SEM) and cathodoluminescence (CL) detector. A cathodoluminescence (CL) microscope combines methods from electron and regular (light optical) microscopes. Ginsberg's group uses multiple approaches, including ultrafast spectroscopy, light microscopy, and cathodoluminescence electron microscopy. This process, called cathodoluminescence, causes the glass to glow, usually yellow-green. Thus, we get secondary and backscattered electrons, X-rays and cathodoluminescence (light). The cathodoluminescence microscope (CLM) is useful for distinguishing phases of refractories. More recently, an angle-resolved cathodoluminescence microscopy system has been developed at the FOM Institute AMOLF. A reddish-violet cathodoluminescence appears on thin-section showing major levels of chlorine, phosphorus, and barium. Cathodoluminescence causes calcite altered in this fashion to glow orange. Cathodoluminescence is light resulting from a luminescent material being struck by electrons. Therefore, in cathodoluminescence, the "semiconductor" examined can, in fact, be almost any non-metallic material. Cathodoluminescence is another mode of detection involving the photons generated by the beam-specimen interaction.