Photon-gated spectral hole burning in LiGa5O8:Co2+

Photon-gated hole burning, or selective bleaching enabled by a second light source, has been observed in Co2+ in tetrahedral sites of LiGa5O8. This leads to long-lived spectral holes with a width of 1 GHz at 1.6 K. It is proposed that two-step photoionization of Co2+ is responsible for the hole burning. Much narrower (40 MHz) transient holes and antiholes were burned using population storage in nuclear hyperfine levels. These two mechanisms of hole burning are reported here for transition-metal ions for what is believed to be the first time. © 1986 The American Physical Society.