Multiwavelength spectroscopy of quantum emitters in hexagonal boron nitride

Defect centers in hexagonal boron nitride (hBN) are promising candidates for integrated single photon sources as they exhibit a set of highly favorable properties such as emission at room-temperature, narrow lines, and photostability. Here, we are reporting on our ongoing efforts to understand the level scheme of defects in hBN. By scanning the excitation laser wavelength information on the excited states is obtained and by multi-colored excitation shelving levels as well as re-pumping wavelengths are analyzed. A detailed analysis of the phonon side bands of hundreds of emitters reveals information on the underlying structure of the defects.