skip to main content

Search for: All records

Creators/Authors contains: "Dubinskii, Mark"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. A comparative study was conducted to investigate the 3.9 µm mid-IR emission properties of Ho3+doped NaYF4and CsCdCl3crystals as well as Ho3+doped Ga2Ge5S13glass. Following optical excitation at ∼890 nm, all the studied materials exhibited broad mid-IR emissions centered at ∼3.9 µm at room temperature. The mid-IR emission at 3.9 µm, originating from the5I55I6transition, showed long emission lifetime values of ∼16.5 ms and ∼1.61 ms for Ho3+doped CsCdCl3crystal and Ga2Ge5S13glass, respectively. Conversely, the Ho3+doped NaYF4crystal exhibited a relatively short lifetime of ∼120 µs. Temperature dependent decay time measurements were performed for the5I5excited state for all three samples. The results showed that the emission lifetimes of Ho3+:CsCdCl3and Ho3+:Ga2Ge5S13were nearly temperature independent over the range studied, while significant emission quenching of the5I5level was observed in Ho3+:NaYF4. The temperature dependence of the multi-phonon relaxation rate for 3.9 µm mid-IR emission in Ho3+:NaYF4crystal was determined. The room temperature stimulated emission cross-sections for all three samples were calculated using the Füchtbauer-Landenburg equation. Furthermore, the results of Judd-Ofelt analysis are presented and discussed.

    more » « less
  2. The mid-IR spectroscopic properties ofEr3+doped low-phononCsCdCl3andCsPbCl3crystals grown by the Bridgman technique have been investigated. Using optical excitations at∼<#comment/>800nmand∼<#comment/>660nm, both crystals exhibited IR emissions at∼<#comment/>1.55,∼<#comment/>2.75,∼<#comment/>3.5, and∼<#comment/>4.5µ<#comment/>mat room temperature. The mid-IR emission at 4.5 µm, originating from the4I9/2→<#comment/>4I11/2transition, showed a long emission lifetime of∼<#comment/>11.6msforEr3+dopedCsCdCl3, whereasEr3+dopedCsPbCl3exhibited a shorter lifetime of∼<#comment/>1.8ms. The measured emission lifetimes of the4I9/2state were nearly independent of the temperature, indicating a negligibly small nonradiative decay rate through multiphonon relaxation, as predicted by the energy-gap law for low-maximum-phonon energy hosts. The room temperature stimulated emission cross sections for the4I9/2→<#comment/>4I11/2transition inEr3+dopedCsCdCl3andCsPbCl3were determined to be∼<#comment/>0.14×<#comment/>10−<#comment/>20cm2and∼<#comment/>0.41×<#comment/>10−<#comment/>20cm2, respectively. The results of Judd–Ofelt analysis are presented and discussed.

    more » « less
  3. We present mid-IR spectroscopic characterization of the low-phonon chalcogenide glass, Ga2Ge5S13(GGS) doped with Er3+ions. Under the excitation at ∼800 nm, Er3+:GGS exhibited broad mid-IR emission bands centered at ∼2.7, ∼3.5, and ∼4.5 µm at room temperature. The emission lifetime of the4I9/2level of Er3+ions in GGS glass was found to be millisecond-long at room temperature. The measured fluorescence lifetimes were nearly independent of temperature, indicating negligibly small nonradiative decay rate for the4I9/2state, as can be expected for a low-maximum-phonon energy host. The transition line-strengths, radiative lifetimes, fluorescence branching ratios were calculated by using the Judd-Ofelt method. The peak stimulated emission cross-section of the4I9/24I11/2transition of Er3+ion was determined to be ∼0.10×10−20cm2at room temperature.

    more » « less