Graded-index characteristics in single-crystal fibers

Single-crystal fibers of Ti(3+):Al(2)O (3)have been grown by the laser-heated pedestal growth technique and shown to exhibit radial refractive-index gradients. A refractive-index increase of approximately 12% in the fiber core with respect to the fiber sidewalls has been measured. The index profile can be fitted with a parabolic model. Postgrowth treatment of Cr(3+):Gd(3)Sc (2)Al (3)O(12)fibers has been shown to produce a uniform cladding region with a graded-index core. The core index is some 12.5% larger than the cladding region, with an index profile shape that is approximately parabolic in nature.