Methods of fabricating extra-mural absorption elements adapted for
incorporation in an image-conducting optical fiber array include
fabricating various constituent components to be included in an optical
fiber bundle from one or more reducible-ion-containing glasses. Various
components fabricated from a reducible-ion-containing glass are
selectively exposed to a reducing atmosphere such that they are
reduction-blackened prior to at least one heating and drawing step
relative to the bundle into which they are to be fusedly incorporated.
Such "pre-blackened" components function as extra-mural absorption media
throughout the length of an image-conducting optical fiber array and
alternatively include fiber claddings and substitutional and interstitial
extra-mural absorption elements.