Glass 3D printed Er³⁺/Yb³⁺ co-doped microsphere laser for high-temperature applications

In this paper, we present an Er³⁺/Yb³⁺ co-doped microsphere laser with an all-glass configuration, with an operating temperature up to 700°C. Glass 3D printing assisted with the laser direct melting technique is applied for Er³⁺/Yb³⁺ co-doped microsphere fabrication, enabling one step microsphere fabrication with the desired Er³⁺/Yb³⁺ concentration and without post treatment. The glass 3D printing process is applied for all-glass microsphere laser encapsulation, including Er³⁺/Yb³⁺ co-doped microsphere and fiber taper coupling structure. Experimental results show that the diameter and rare earth concentration of Er³⁺/Yb³⁺ co-doped microspheres can be precisely controlled. Q factor of glass-encapsulated Er³⁺/Yb³⁺ co-doped microsphere is maintained at 3.1 × 10⁵. Dual-wavelength lasing is demonstrated for the all-glass microsphere laser at temperatures up to 700 °C, exhibiting temperature sensitivity of 11.8 pm/°C in the range of 300-380 °C. With the advantages of all-glass configuration, enhanced robustness, and high-temperature survivability, the glass 3D printed Er³⁺/Yb³⁺ co-doped microsphere laser demonstrates significant potential for high-temperature applications.