Abstract: An optical isolator for improving the isolation between an optical source and a transmission link in an optical communications system. The optical isolator comprises a tapered lens including a core region and surrounding cladding material. The core region can be fabricated from graded or step index glass and the cladding can be fabricated from glass or polymer material. The core region can also be fabricated from graded or step index polymer material with the cladding fabricated from polymer material. An opaque disk of carbon-filled epoxy is deposited on the large diameter end of the optical isolator to further enhance isolation.

Abstract: A metallic material coating is applied to the external surface of a freshly drawn optical fiber while such surface is still pristine by passing the optical fiber through a body of liquid metal-organic material which forms a layer on the fiber, and by subsequently removing all non-metallic components from the layer of metal-organic material by volatilizing the same. The optical fiber with the layer metal-organic material is passed through a baking oven in which at least the layer is heated to a baking temperature at which organic materials present in the metal-organic material are volatilized and the remainder is baked to the fiber. Then, at least the layer is fired in a firing chamber at a higher temperature at which the metal-organic material is decomposed into its volatile non-metallic and non-volatile metallic components, the latter remaining in the layer and the former becoming volatile and leaving the layer.