Nair, S.R.S.R.NairRogers, L.J.L.J.RogersJeske, JanJanJeskeVidal, X.X.VidalWood, A.A.WoodJelezko, F.F.JelezkoGreentree, A.D.A.D.GreentreeVolz, T.T.Volz2022-03-142022-03-142019https://publica.fraunhofer.de/handle/publica/41094910.1109/CLEOE-EQEC.2019.8872972Summary form only given. Magnetic sensing with lasing from negatively charged nitorgen-vacancy (NV) centres in diamond is predicted to reach fT/SRHz regime even at room temperature [1]. Stimulated emission from NV centres has already been explored as a stepping stone towards such a laser magnetometer [2, 3, 4]. Here we report the observation of amplification on the cavity transmission of an open fibre cavity formed between a fibre-mirror and a macroscopic mirror, loaded with a high NV density diamond sample. On adding green laser light to optically pump the NV centres, we observe amplification on the transmitted seed wavelength close to 720 nm up to a factor around 3.en667conference paper