Hollow waveguides present an alternative to solid core fibers in the IR regime where suitable optical materials are scarce. Due to their air core, they can also be used for broad-spectrum high power transmission due to small insertion losses. This makes them suitable for use in industrial or medical applications or for spectroscopic and radiometric measurements. Conventional hollow waveguides rely on multimode operation; however, this technology allows for the excitation of only a single waveguide mode making it well-suited for certain devices like hollow waveguide lasers.