Abstract: An all-fiber erbium laser oscillating in a passive Q switched mode. The laser includes a crystal saturable absorber that may be Co2+:ZnSe or Cr2+:ZnSe. In preferred embodiments continuous pumping or short pulse pumping may be utilized. The laser is characterized by low threshold high-power, short-pulse generation. In preferred embodiments the threshold is only about 20 mW. The crystals are bleached at extremely low intensity, of about 0.8 kW/cm2 and provide moderate relaxation time of the excited state (290 ?s) within a spectral range of about 1400-1800 nm. The simplicity of the design and low cost of that laser 2000).