Optimized monolithic edge-cladding glass for N31-type Nd-doped high power laser glass

In this paper, six edge-cladding glasses are prepared and analyzed, which are designed to clad the elliptical disk of N31-type Nd-doped phosphate laser glass by monolithic edge-cladding technique. The transition temperatures, soften temperatures, thermal expansion coefficients, high temperature viscosities and refractive indices of the prepared edge-cladding glasses are determined, which must be consistent with these parameters of N31 glass as possible. The residual stresses and residual reflectivities are determined for the cladded N31 elliptical disks and slab samples, which are the most important parameters for the monolithic edge-cladding technique and must be as low as possible to meet the index requirements for high power laser applications. The interface bubbles, edge-cladding interface and the controllability of divalent Cu2+ ions are also discussed. By the optimized edge-cladding glass, it is verified that the elliptical disk of N31-type Nd-doped phosphate laser glass can be successfully cladded by the optimized monolithic edge-cladding glass, which can be utilized securely in a strong liquid cooling to pursue a better high-power laser performance with a higher laser shot rate. •The designed edge-cladding glass for N31 laser glass is optimized with almost the same thermal expansion coefficient and refractive index of N31.•The optimized edge-cladding glass can be applied in monolithic edge-cladding, pursuing sufficiently low residual stress and residual reflectivity.•By the optimized edge-cladding glass, the monolithic edge-cladded elliptical N31 laser glass disk can be utilized in liquid cooling conditions.