Abstract: With the development of high-power solid-state lasers and fiber lasers， the demand for optical isolators in the visible to near-infrared region is gradually increasing， necessitating the exploration of novel magneto-optical crystals to meet development requirements. In this paper， high-quality dysprosium aluminum garnet （Dy₃Al₅O₁₂， DyAG） single-crystal fibers were grown using the laser-heated pedestal growth method. The growth process of the crystals was investigated， and their fundamental physical properties were studied. XRD patterns show that， the crystal structure of DyAG fiber is consistent with that of conventional garnets， belonging to the cubic crystal system with space group of ${Ia} \overline{3} d$ and lattice parameters of a=b=c=11.974 Å. The crystal samples exhibit narrow diffraction peak full width at half maximum， indicating excellent crystalline quality. The electronic structure of DyAG fiber was calculated using first-principles method and the results reveal a relatively wide bandgap of 4.311 eV， with a refractive index maintained at approximately 1.93 for wavelengths greater than 500 nm. Further characterization and analysis of the crystal's optical properties reveal its excellent light transmittance in the wavelength range from 475 nm to 700 nm， achieving a transmittance of 77.5% which is nearly reaching the theoretical value of 80.8%. This makes it promising for application in magneto-optical devices operating within this spectral band.

Key words: single-crystal fiber; DyAG; laser heated pedestal growth method; crystal growth; magneto-optical crystal