Recently we reported about laser action on the 3H43H6 transition of Tm3+ ion when it is excited due to energy transfer from four-fold co-ordinated Cr4+(t) ions in YAG crystal [1,2]. 2.02 um CW oscillation was performed by 1.06 CW Nd laser pumping. The lasing threshold was about 3 W. It is correspond to 15% quantum efficiency of energy transfer from a Cr4+(t) ion to a Tm3+ ion. On the other hand the quantum efficiency was equal to 90 % by the pulsed pumping as it was obtained from measuring of Cr4+(t) luminescence relaxation time. We supported some cause reducing the quantum efficiency of energy transfer from Cr4+(t) ions to a Tm3+ ions with CW pumping. So far as an excited Tm3+ ions density, is needed for lasing, (which we estimated as 1020cm−3) is considerably higher than the Cr4+ ions concentration (it is equal to 3.1*1017 cm−3), excitation migration in Tm3+ ions system must take place after excitation transfer from a Cr4+ ion to a Tm3+ ion to reach the necessary excitation density. But a migration rate in Tm3+ system is expected lower than an excitation transfer rate from a Cr4+ to a Tm3+ ion, therefore excited Tm3+ ions will be concentrated near a Cr4+(t) being souse of excitation. So a local saturation of Tm3+ ions excitation may take place, that will cause reducing of energy transfer rate from Cr4+(t) ions to Tm3+ ions. In order to evaluate the energy transfer rate by CW pumping we had measured depandences of transmittance of YAG: YAG:Tm3+, Cr4+ and YAG:Cr4+ crystals upon the pumping power up to the power density corresponding to our lasing experiments.

© 1995 Optical Society of America

PDF Article
More Like This
Energy transfer from Ce3+ and Cr4+ to Er3+ ions in garnet and yttrium silicate crystals

V. B. Sigachev, M. E. Doroshenko, M. I. Timoshechkin, G. B. Loutts, and B. H. T. Chai
CTuK66 Conference on Lasers and Electro-Optics (CLEO) 1994

Energy-Transfer Processes among Cr, Tm, and Ho Ions in Yttrium Aluminum Garnet Crystals

G. Armagan, A. M. Buoncristiani, B. Di Bartolo, A. T. Inge, and C. H. Bair
EE7 Advanced Solid State Lasers (ASSL) 1989

Energy Transfer (Tm→Ho) and Upconversion Processes in YSGG:Cr3+:Tm3+:Ho3+ Laser Crystals

M A. Noginov, S. G. Semenkov, I. A. Shcherbakov, V. A. Smirnov, and D. A. Zubenko
MIL5 Advanced Solid State Lasers (ASSL) 1991


You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
Login to access OSA Member Subscription