The ability to produce robust fiber-based integrated optical systems operating over a wide spectral domain (UV to mid-infrared), is one of today's key challenges in photonics. This work reports on the production of crystal-free, light guiding fibers from rich Ga2O3 oxide-based glass compositions. These materials show optical transmission extending from ultraviolet wavelengths (similar to 0.280 mu m) up to 6 mu m in the IR for millimeter length scale while exhibiting relatively high vitreous transition temperatures (similar to 735 degrees C), nonlinear optical properties and improved surface micro-hardness. This combination of superior thermal, mechanical and optical properties represents a promising alternative for the development of robust fibers operating in the visible up to the 3-5 mu m window. (c) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement