Er, Yb: Glass

Er³⁺/Yb³⁺ co-doped phosphate glass — as the 1540nm eye-safe radiation sources pumped by LD which can emit eye-safe 1540nm laser radiation directly used in laser ranging finder and telecommunication communication

As an eye-safe wavelength laser, 1540um, Er³⁺/Yb³⁺ co-doped phosphate glass lasers have attracted much attention for their compactness and low costs, such as laser generation and signal amplification wavelength of 1540nm is just at the position of the eye-safe and the fiber optic communication window. 1540nm lasers have been used in ranging finder, radar, and target recognition. Er³⁺/Yb³⁺ co-doped phosphate glass cooperates with passive Q-Switch crystal – co:spinel to get a 1540nm pulse solid-state laser.

Er³⁺ emission transition occurs within this wavelength range corresponding to the ⁴I_13/2 →⁴I_15/2. However, Er³⁺ absorption is too weak to allow direct pumping, so energy transfers are required. Yb³⁺ ions give the most efficient ones under absorption from the ²F_7/2 → ²F_5/2 transition, energy transfer to the ⁴I_11/2 Er³⁺ level and fast nonradiative change Er^{3+  4}I_13/2 level, which emits the expected fluorescence. Er,Yb:glass laser with radiation output at the wavelength of 1540 nm does not require the addition of additional components.