METHOD OF PROCESSING END-FACES OF AIR-CLAD AND PHOTONIC-CRYSTAL FIBERS, AND FIBERS PRODUCED THEREBY

摘要

A method of preventing contamination of the air channels in the capillaries or pores of an air-clad or photonic-crystal fiber during polishing of the end-faces. A glass or silica fiber rod of diameter comparable to the fiber is fused to the end-face of the fiber, cut, and polished to form a thin protective plate having no appreciable affect on the optical properties of the fiber. Alternatively the air capillaries may be sealed by a UV-curable fluid or by melting the surrounding material. The end-face of the fiber thus presents a polished or cleaved surface for optical coupling to other fibers without causing damage or contamination to the air channels of the fiber. Furthermore, treating both end-faces of an air-clad or photonic-crystal fiber in this manner provides a hermetic seal for the air-channels and protects the fiber against degradation caused by contamination such as humidity and dust, which would otherwise enter the air channels over the course of time. Furthermore, there is a reduction in power density at the end-face of the fiber, which reduces the risk of damage. Anti-reflective coatings are consequently easier to apply and more stable. In addition to protecting the end-face of an air-clad or photonic-crystal fiber with a thin plate, it is also possible to utilize a graded-index (GRIN) element to perform both the protective function as well as an optical function.