Enhanced rare-earth ion doping in silica glass by photopolymerization for microlaser

The photopolymerization method for fabricating silica glass is a rapid, eco-friendly, and flexible technique. However, silica glass prepared via this method has limited solubility for rare-earth ions, making it difficult to achieve laser output with such low luminescence efficiency. Here, Al and P elements are introduced into the silica glass matrix to increase the Yb3+ doping concentration to 1.2 wt%. It is revealed that the fluorescence intensity of the co-doped silica glass is greatly enhanced, making it more suitable as a laser gain material. A porous glass rod co-doped with Al/P/Yb is fabricated based on the above method, subsequently transforming it into a glass microsphere resonator through treatment with a hydrogen-oxygen flame and CO2 laser. By pumping with a tapered optical fiber, the output of multi-mode (1033 nm and 1040 nm) lasers is achieved in whispering gallery modes (WGMs) resonator. This technology offers a simpler and more efficient method for fabricating laser microsphere resonators, which holds promise for applications in the field of integrated optics.