Influence of Argon Deposition Pressure on the Mid-Infrared Luminescence of Dysprosium-Doped Ga–Ge–Sb–Se Waveguides Deposited on Different Substrates

Radiofrequency (RF) magnetron sputtering is used to deposit 5000 ppmw Dy3+-doped selenide thin films on SiO2 or undoped sulfide confinement layers on silicon substrates. Then, photolithography and dry etching techniques are implemented to fabricate rare-earth-doped selenide ridge waveguides. The investigation was focused on the influence of argon deposition pressure on amorphous chalcogenide thin films’ properties with special attention to luminescence. Fluorescence in short-wave and midwave infrared spectral ranges is recorded using optical excitation at 1.32 μm. The argon pressure of 1 × 10–2 mbar gives the highest and clearest signal in the midwave infrared region. At 4.38 μm, single-mode optical propagation is efficiently observed in 5000 ppmw Dy3+-doped Ga5Ge20Sb10Se65 waveguides deposited on an undoped sulfide confinement layer on the silicon substrate.