Abstract

The mid-infrared (MIR) photonics market is rapidly expanding, driven by advancements in fiber-based MIR devices, particularly fiber lasers. However, the lack of robust MIR optical fibers remains a critical barrier to further technological progress. In this work, we present the fabrication of gallate glasses containing tantalum oxide, as it stands, the most robust mid-infrared glasses capable of being easily shaped into large bulk components, fibers or tapers. By introducing up to 20 mol% of tantalum oxide in a gallate glass, we achieve a two-order-of-magnitude improvement in water corrosion resistance, while the nonlinear refractive index increases tenfold compared to silica. Optimal thermal stability is attained at 10 mol% of tantalum oxide, enabling the fabrication of tens-of-meter-long optical fibers. Crucially, the addition of tantalum oxide enhances the gallate glass properties without compromising thermomechanical performance. The potential of these tantalo-gallate glasses is further demonstrated through supercontinuum generation in a laser-inscribed waveguide and a tapered fiber, spanning from the visible to 4.5 μm. This work establishes our developed tantalo-gallate glasses as a compelling alternative for photonic applications seeking robust mid-infrared materials, with the potential to overcome the critical barriers currently limiting the advancement of fiber-based MIR technologies.