Quasi-2D GaN layers inserted in an AlGaN matrix are proposed as a novel active region to develop a high-output-power UV light source. Such a structure is successfully achieved by precise control in molecular beam epitaxy and shows an amazing output power of approximate to 160 mW at 285 nm with a pulsed electron-beam excitation. This device is promising and competitive in non-line-of-sight communications or the sterilization field.