Coordination geometry engineering in a doped disordered matrix for tunable optical response

Abstract

The controllable incorporation of the dopant element with strictly designed coordination geometry into the target host merits untold scientific and technological potential, yet it has been met with limited success in a disordered matrix. Here, we present a general route for precisely tuning the coordination geometry of the transition metal dopant based on the collaborative element hybridization and crystallization. We experimentally realize the effective switch of tetrahedral and octahedral geometry by using the proof-of-concept Co2+ dopant in hybrid glass. We identify that the crystal field stabilization energy should be genetic dominating the above process. The stabilization of high-yield [CoO4]6- tetrahedron and [CoF6]4- octahedron in glass enables it to exhibit unique photon-electron-photon effects, including the efficient radiative transition in the blind region of rare earth-doped materials from 2200 to 2600 nm with new record bandwidth (570 nm) and dynamic optical modulation for pulse generation with the duration of 280 ns. The results demonstrate that the proposed strategy provides an effective avenue to construct novel photonic components with multifunctional applications from broadband telecommunication, medical diagnostics, and military countermeasure to trace gas monitoring.