The passively q-switched diode end-pumped solid-state laser is used the gain medium made of Er:Yb doped crystal and the Q-switch made of Co2+:MgAl2O4 crystal. The optical elements are optimally designed for the resonator to achieve pulse energy in a range 0.5 mJ≤E≤2 mJ with the pulse width in a range of 4 ns-15 ns. The resonator is appropriate to use in laser rangefinders, target designator, and other products in military and civilian applications.