Abstract How does one pass a photon through a tube with a diameter 1/100 or 1/1000 that of its wavelength? This question is relevant to our production of a subwavelength light source. Schematically, it is a concentric, conical, gold-coated, glass tube with an inner diameter tapering down from about 5 to 0.05 microns into which a crystal of anthracene was grown. It is illuminated on the large end by UV light from a CW argon-ion laser. It emits (from the small end) an evanescent beam of blue light (about 105 photons/sec). This EXCITOR (exciton transmitted optical radiation) source has been used as a scanning tip for near-field optical microscopy. The theoretical resolution limit is about 100 times below the diffraction limit. the same EXCITOR tip is also a Scanning Forster donor (exciton transfer probe). For instance, it is quenched by a thin (transparent) gold layer at distances below 100 A.