title: Infrared radiation properties of Ho³⁺ in multicomponent germanium tellurite glasses.
abstract: Ho(3+)-doped and Ho(3+)/Yb(3+)-codoped multicomponent germanium tellurite (MGT) glasses with multifarious emission channels in the near-infrared wavelength region have been fabricated and characterized. Judd-Ofelt intensity parameters of Ho(3+)-doped MGT glasses are solved to be Ω2=5.32×10(-20)  cm(2), Ω(4)=2.73×10(-20)  cm(2), and Ω(6)=1.12×10(-20)  cm(2), indicating a higher asymmetric and stronger covalent environment around Ho(3+) ions in MGT glasses. Efficient infrared fluorescences have been observed in MGT glasses, and spontaneous emission probabilities are derived to be 230.4, 79.9, and 138.3  s(-1) for the (5)I(6)→(5)I(8), ((5)F(4),(5)S(2))→(5)I(5), and (5)I(7)→(5)I(8) radiative transitions, respectively. In Ho(3+)/Yb(3+)-codoped MGT glasses, the maximum stimulated emission cross-section of 2.0 μm emission is calculated to be 4.93×10(-21)  cm(2), and the corresponding gain cross-section is derived to be 3.62×10(-21)  cm(2) when the excited state population fraction P reaches 0.8. Multifarious infrared emissions show that Ho(3+) in MGT glasses is a good candidate for optical amplifiers and optoelectronic devices.
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Sui
authors.forename: B J
authors.initials: BJ
authors.lastname: Chen
authors.forename: E Y B
authors.initials: EY
authors.lastname: Pun
authors.forename: H
authors.initials: H
authors.lastname: Lin
mesh_terms: D004867:Equipment Design; D005453:Fluorescence; D005857:Germanium / Q000737:chemistry*; D005898:Glass; D006695:Holmium / Q000737:chemistry*; D006358:Hot Temperature; D007259:Infrared Rays; D049449:Luminescence; D055096:Optical Devices; D055095:Optics and Photonics; D011336:Probability; D013053:Spectrophotometry / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared; D013691:Tellurium / Q000737:chemistry*; D013696:Temperature; D015018:Ytterbium / Q000737:chemistry
chemical_list: D005857:Germanium; C026660:tellurous acid; D015018:Ytterbium; D013691:Tellurium; D006695:Holmium