Laser action at 530 nm using H3 centers in diamond was observed with an efficiency of 13.5% at room temperature. Optical double-resonance experiments on N3 centers provided direct evidence for a 2A metastable level. Its presence results in rapid decay of the excited 2E state and low quantum efficiency as well as significant excited-state absorption in the N3 luminescence region.
© 1985 Optical Society of America
S. C. Rand and L. G. DeShazer, "Visible color-center laser in diamond," Opt. Lett. 10, 481-483 (1985)