Nd³⁺-doped ion-exchanged aluminum germanate glass channel waveguide

K⁺-Na⁺ ion-exchanged channel waveguide has been fabricated in Nd³⁺ doped aluminum germanate (NMAG) glasses with potential photosensitive property. The channel waveguide exhibits single mode at 1.3μm and the mode field diameters were measured to be horizontally 10.1μm and vertically 5.3μm, respectively. Amplified spontaneous emissions (ASE) of 905, 1060, 1334 and 1816nm originating from the ⁴F_3/2 level were recorded under ~800nm diode laser pumping and the maximum stimulated emission cross-sections for the ⁴F_3/2 → ⁴I_11/2 and ⁴F_3/2 → ⁴I_13/2 transitions are derived to be 21.5 × 10^-21 and 7.6 × 10^-21cm², respectively. In addition, with 71.8% quantum efficiency and the largest emission intensity among various Nd³⁺ doping cases, 2wt% Nd₂O₃ is considered as the optimized doping concentration for the compact channel waveguide. The ion-exchanged Nd³⁺-doped NMAG glass channel waveguides offer favorable prospects for the development of optical waveguide amplifiers, broadband light sources and infrared UV-written grating waveguide lasers.