Lanthanide composite as doping reagent simplifies and uniformizes deposition of fiber preforms

Abstract

Controlling the volatilization and diffusion of co-dopants to afford the uniform distribution of co-doping lanthanide elements with appropriate concentration is crucial to ytterbium (Yb)/erbium (Er) co-doped fiber preforms. Here, volatile and thermostable lanthanide composite Yb_0.95Er_0.05(thd)₃ is proposed and demonstrated to practicably regulate the doping concentration by the fixed Yb/Er molar ratio in the formation, suitable for continuous deposition with simply one raw material transfer line for both Yb and Er elements. Benefiting from more uniform distributions and higher Yb→Er energy transfer efficiency, stronger Er^III-based emission of the Er/Yb co-doped fiber preforms prepared with Yb_0.95Er_0.05(thd)₃ than that with traditional Yb(thd)₃/Er(thd)₃ is achieved. This work highlights the advantage of this lanthanide composite as a doping reagent in simplifying and uniformizing the deposition of lanthanide-doped fiber preforms, and it establishes the relationship between the doping reagent at molecular levels and the performance of fiber preforms.