Rare-Earth Spontaneous Emission Control in Three-Dimensional Lithium Niobate Photonic Crystals

Although majorexperimental breakthroughs have already been achieved, thefundamental limiting challenge still inheres in the achievementof experimental methods capable of 3D-sculpting any desiredmedium with nanometric resolution. This technical limitationhas caused many of the anticipated optical quantum devices tocontinuebeingpracticallyunattainable.