Lai, C.-C.C.-C.LaiLin, Y.-S.Y.-S.LinHuang, K.-Y.K.-Y.HuangSHENG-LUNG HUANG2018-09-102018-09-10201000218979http://www.scopus.com/inward/record.url?eid=2-s2.0-77956811028&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/357926This study reports, for the first time, atomic-scale high-resolution transmission electron microscope (HRTEM) microstructure studies on the interface between the crystal core and polycrystalline inner cladding and strain relaxation mechanism of high-quality Cr:YAG double-clad crystal fibers grown by a codrawing laser-heated pedestal growth method. HRTEM analysis indicates that the core has high crystallinity and a sharp core/inner-cladding interface, exhibiting coherent planes with a preferred orientation relationship to the γ-Al2 O3 nanocrystals in the inner cladding. The slightly distorted γ -Al2 O3 lattice facilitates the release of residual strain, and eliminates misfit dislocation at the interface. Lattice strain analysis and image processing reveal a ∼18.2 nm layer near the interface for strain relaxation. © 2010 American Institute of Physics.Atomic scale; Cladding interfaces; Crystal fiber; Double-clad; High crystallinity; High quality; High-resolution transmission electron microscopes; HRTEM analysis; Inner cladding; Laser heated pedestal growth; Lattice strain analysis; Misfit dislocations; Polycrystalline; Preferred orientations; Residual strains; Strain relaxation mechanism; YAG; Chromium; Crystal whiskers; Dislocations (crystals); Image processing; Strain control; Strain relaxation; Transmission electron microscopy; Crystal microstructurejournal article10.1063/1.34675172-s2.0-77956811028