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 cost, such as laser generation and signal amplification because the wavelength of 1540nm is just at the position of the eye-safe and the fiber optic communication window. 1540nm lasers have used in ranging finder, radar, target recognition. Er3+/Yb3+ co-doped phosphate glass cooperate with passive Q-Switch crystal -co:spinel to get 1540nm pulse solid-state laser.

Er3+ emission transition occurs within this wavelength range corresponding to the 4I13/2 →4I15/2 . However, Er3+ absorption itself is too weak to allow direct pumping and so, energy transfers are required. The most efficient ones are given by Yb3+ ions under absorption from the 2F7/2 → 2F5/2 transition, followed by energy transfer to the 4I11/2 Er3+ level and fast nonradiative transition to the Er3+  4I13/2 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.