Fabrication of optical layers containing Er(III) and Cu(I) in silicate glasses Original Research Article

Optical materials containing Cu+ have recently become a subject of considerable interest for their potential application in tunable lasers emitting in the blue-green spectral region. The emission is the result of the Cu+ transition 3d10↔3d94s1. One of the main problems we solved was the sufficient stabilization of Cu+ and the prevention of its oxidation to Cu2+. We present our approach to the fabrication of Cu+ containing slab waveguides up to 10 μm deep in specially designed sodium-zincsilicate glasses doped with erbium. The erbium atoms when present in a glass matrix lower its permeability for diffusing ions. Therefore, we formulated novel glasses with a higher sodium content having more open structure and stabilizing the Cu+ ions. The Cu+ waveguides were fabricated using the ion exchange technology in melts where CuI was a key component. The characterization of prepared samples included composition analysis with special attention paid to the oxidation states of copper and optical/waveguiding properties’ measurements focused on the blue-green emission. Our experiments revealed that the coordination of copper ions in a glass matrix significantly influences the position of the blue-green luminescence band that can be tuned by modifying a glass composition.