Laser ions thulium

Johnson et al. (55) observed energy transfer from erbium to thulium and from erbium to holmium ions in crystals. They were able to obtain substantial decreases in laser thresholds because of this energy migration. The fluorescent lifetime of the 3//4 state of thulium in CaMo04 containing 0.75 atomic per cent erbium and 0.5 atomic per cent thulium as inferred from the time delay before the onset of laser oscillation is 900 /xsec at both IT and 20°K. 

The MCI2 (M = Ca, Sr, and Ba) crystals are ideal candidates for studies of the spectroscopic properties of Tm " ions. First, no charge-compensation defects are required after thulium ions are introduced into these hosts. Second, there is reliable experimental information about the absorption/emission spectra of these materials [2-8]. Moreover, the earth-alkaline halides are also important from an application point of view because the laser action has been achieved in CaF2 Tm [9]. The spectra of Tm " were modeled in our earlier publication [10]. 

The incorporation of metallic NPs in RE-doped glasses has been intensively investigated in recent years for its positive effects on the PL behaviors of RE ions. Among various RE ions, the trivalent thulium ion exhibits rich emissions from visible bands to the mid-lR region, and its absorption band for the H4 state at 0.8 pm facilitates the use of the commercial GaAlAs diode laser as a pump source. In the present work, the NIR PL spectra of the Tm -doped 70GeS2-... 

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