title: Simple and efficient defect-tailored fiber-based UV-VIS broadband white light generation.
abstract: We propose and demonstrate a facile approach for ultraviolet-visible broadband generation from a sapphire crystal core-borosilicate glass cladding hybrid fiber using a laser-heated pedestal growth technique. Considerable formation of F- and F(2)-type color emitters is effectively facilitated by Ti(4+) ions and Al(3+) vacancies, retaining efficient luminescence and high crystallinity of the sapphire core. These color centers intensify the ultraviolet, blue, and green emissions at 370, 450, and 540 nm, whereas the 650-nm red emission is contributed by Cr(3+) in the octahedral sites of the corundum structure. Over 1-mW white light with an optical-to-optical efficiency of up to nearly 5% and 1931 Commission International de l'Eclairage chromaticity coordinate of (0.287, 0.333) is achieved under 325-nm excitation.
authors.affiliation: Department of Physics, National Dong Hwa University, Hualien 97401, Taiwan. cclai@mail.ndhu.edu.tw
authors.forename: Chien-Chih
authors.initials: CC
authors.lastname: Lai
authors.forename: Nai-Chia
authors.initials: NC
authors.lastname: Cheng
authors.forename: Cheng-Kai
authors.initials: CK
authors.lastname: Wang
authors.forename: Jeng-Wei
authors.initials: JW
authors.lastname: Tjiu
authors.forename: Ming-Yi
authors.initials: MY
authors.lastname: Lin
authors.forename: Sheng-Yao
authors.initials: SY
authors.lastname: Huang
mesh_terms: D003116:Color; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007834:Lasers; D008029:Lighting / Q000295:instrumentation*; D014466:Ultraviolet Rays