High average power (105†W) Fe:ZnSe laser pumped by radiation of laser diode side-pumped Er:YAG lasers.

ABSTRACT

A high average power re-frequency operation FeZnSe laser using laser diode side-pumped free-running ErYAG lasers as activating sources is presented. Two pieces of subsurface layer doped FeZnSe polycrystal are adoptive in a reflective resonator configuration and face-cooled by liquid nitrogen. A maximal FeZnSe laser power of 105 W at a wavelength of 4.1 µm is achieved upon pumping by ten home-made ErYAG lasers with fiber coupled output working at a frequency of 250 Hz and a pulse duration of ∼420 µs. Corresponding to the maximum FeZnSe laser power, the optical-optical efficiency and slope efficiency with respect to the absorbed pump power are 43% and 44% respectively. The beam quality factor M2 is measured to be 3.4. To the best of our knowledge, it is the highest output average power of an FeZnSe laser reported.