Broadband near-infrared emission in Tm^3+-Dy^3+ codoped amorphous chalcohalide films fabricated by pulsed laser deposition

Structural and near-infrared (NIR) emission properties were investigated in the Tm(3+)-Dy(3+) codoped Ge-Ga-based amorphous chalcohalide films fabricated by pulsed laser deposition. The homogeneous films illustrated similar random network to the glass target according to the measurements of X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. An 808 nm laser diode pumping generated a superbroadband NIR emission ranging from 1050 to 1570 nm and the other intense broadband NIR emission centered at ~1800 nm, which was attributed to the efficient energy transfer from Tm(3+) to Dy(3+) ions. This was further verified by the broad-range excitation measurements near the Urbach optical-absorption edge involved defect states. The results shed light on the potential highly integrated planar optical device applications of the codoped amorphous chalcohalide films.