A near-field scanning optical probe comprises an optical fiber for conducting
imaging
light therethrough, the fiber having at least a portion doped with an optical gain
medium and further having a tapered end portion with a frustoconical wall and an
end surface for emitting the imaging light. In use, pumping light and optionally
imaging light are coupled into the optical fiber such that the pumping light excites
the optical gain medium to a higher energy state to emit photons at the approximate
wavelength of the imaging light desired, to thereby produce and optionally amplify
the imaging light emitted by the probe.