A field emission light source using cathodoluminescent (CL) phosphors and a reticulated vitreous carbon (RVC) cathode is presented. The flat-format design requires no microfabrication technology and can be easily configured for light emission at different wavelengths, ranging from UV to visible, to infrared. The operation of a visible-spectrum light source was demonstrated by testing both unpackaged devices in a vacuum environment and proof-of-concept packaged lamps. The results exhibited excellent field emission properties with a minimum extraction field of 1.7 V/ m and good uniformity. Luminance characteristics were also excellent, with a white CL phosphor being excited up to approximately 12 000 Cd/m . Lower levels of luminance are applicable to display backlights.