A method of operating a Tm:doped fiber amplifier including selecting a length of Tm:doped optical fiber to be less than one hundred meters, doping the optical fiber with active ions at a doping level of greater than one percent, optically pumping the doped optical fiber with a first laser beam having a wavelength longer than the wavelength where a maximum absorption cross section is provided by the active ions, and creating a population inversion between two active ion energy levels with the first laser beam, the active ions providing a gain to a second laser beam.
