The world’s smallest three-dimensional optical cavities with the potential to generate the world’s most intense nanolaser beams have been created by a scientific team led by researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley. In addition to nanolasers, these unique optical cavities with their extraordinary electromagnetic properties should be applicable to a broad range of other technologies, including LEDs, optical sensing, nonlinear optics, quantum optics and photonic integrated circuits.