Ho-doped tellurite glasses for emission in the mid infrared wavelength region

Here the emission of Ho
³⁺
ions at 2.1 μm in tellurite glasses was explored by fabricating a single mode double cladding Ho-doped tellurite optical fiber, co-doped with Tm
³⁺
ions to allow pumping at 793 nm. The intention was to optimize a fiber for future single mode narrow linewidth compact fiber laser for Lidar systems. The fiber was characterized both morphologically and in its optical properties: optical attenuation losses were measured; fluorescence spectra both in the visible and in the infrared wavelength region were recorded by pumping the fiber core with a 793 nm SM diode laser.