Growth of crystalline claddings on single crystal fiber (Conference Presentation)

Abstract

Single crystal fiber composed of rare earth doped YAG offers the potential for high power scaling of fiber lasers due to it lower intrinsic stimulated Brillouin cross-sections and higher thermal conductivity. The use of rare earth doped YAG fibers also mitigates issues associated with photodarkening, as well as issues associated with the silica multiphonon edge absorption and OH- quenching observed in Ho doped silica fiber lasers operating at eye safer wavelengths. To date, small diameter single crystal YAG fibers as small as 17 µm have been grown at Naval Research Laboratory to achieve a core architecture. Recent work has focused on development of cladding structures on the single crystal core material through sputtering, liquid phase epitaxy, and hydrothermal crystal growth to achieve a true core/clad all- crystalline wave guiding structure. Crystalline claddings have been grown with all three approaches with varying degree of quality and crystallinity. In this paper, we will report on our progress in fabricating crystal claddings on YAG single crystal core material.