Study Of Dual Band Er-doped ZBLAN Fiber Laser

With the characteristics of compact structure,good luminescence and high integration,the near-infrared and mid-infrared fiber lasers output in the 3?m and 2?m wavelength bands have become the preferred application tool in the field of military and civil,such as laser communication,environmental testing,biological therapy,infrared guidance,molecular identification and so on.Therefore,the rare-earth-doped ZBLAN fiber laser technology used to achieve the output of these two bands is the core of the development of various industries now.In this paper,based on the deep study of the Er³⁺ion state system and luminescence characteristics,the differential equations and boundary conditions satisfied by the Er³⁺-doped ZBLAN cascade fiber laser were derived with the principle of three energy rate equations.And the specific numerical simulation of the ion differential equation and the power conduction equation was carried out by the MATLAB simulation software.The related features of the cascaded Er³⁺-doped ZBLAN fiber laser were mainly described in steady state.According to the above results,an Er³⁺-doped ZBLAN fiber laser system was built to achieve simultaneous output of 2.8?m and 1.6?m lasers.In which a domestic LD laser with an output wavelength of 980nm was used to excite a fluoride optical fiber gain medium with a length of 4m,a core diameter of 30?m,a numerical aperture of 0.12 and a cladding diameter of 300?m.In the case of the maximum pump power of 5W,the continuous dual wavelength output with the center wavelength of 2803nm and 1610nm respectively was realized.The corresponding maximum output power was 362.4mW and108.6mW respectively,and the slope efficiency reached 12.1%and 4.94%respectively.In addition,under the maximum pump power,the floating ratio of the peak power of the above two wavelengths in 4 hours was 9.7%and 2.1%in turn.It indicated that this laser system had relatively high stability.