Spectroscopic properties of Ni2+ and rare-earth codoped Ge–Ga–Sb–S glass

The infrared emission properties of rare-earth (i.e., Dy3+, Pr3+ or Sm3+) and nickel-codoped Ge–Ga–Sb–S glasses were investigated by photoluminescence measurements. It was found that the emission intensities of the rare-earth doped glasses were significantly weakened even with very few amount of nickel (i.e., 500 at. ppm). On the other hand, the nickel-doped glasses show larger indices of refraction, which property will be desirable in nonlinear optics. Our results, however, suggest that to obtain rare-earth doped chalcogenide glasses of better infrared emission property it is necessary to keep the nickel dopant as low as possible.