Divalent and Trivalent Europium Doped Alumina Waveguides Elaborated by Pulsed Laser Deposition

ABSTRACTEuropium doped alumina Al2O3optical waveguides were prepared by pulsed laser deposition (PLD) using a KrF laser. The targets were obtained by sintering doped powders synthesized by a sol-gel method. Depending on the oxygen pressure used during the deposition, Eu3+ (for 0.1 mbar) or Eu2+ (for 10−5 mbar) are obtained in the films. Two kinds of Eu2+ ions are present, with a 4f-5d broad excitation band peaking at 330 nm and emission bands located at 490 nm or 585 nm respectively. For Eu3+ doped films, the usual 5D0 to the 7FJ multiplets emission spectra were observed. The emission lines are strongly inhomogeneously broadened. Low temperature site selective fluorescence measurements were achieved in order to correlate the different Eu3+ sites observed with the structure of the films (amorphous or γ crystallized).