JOES - Judd Ofelt from emission spectrum

Application software for complete Judd-Ofelt analysis from the emission spectrum of europium doped materials

What is Judd-Ofelt theory?

Judd-Ofelt theory has the ability to predict oscillator strengths in both absorption and luminescence, luminescence branching rations, excited state radiative lifetimes, energy-transfer probabilities and estimates of quantum efficiencies by using only three parameters. Its predictive qualities are responsible for its widespread use in all fields regarding luminescence of rare earths. Rapid increase of the importance of the field of lanthanide materials is followed by an increasing trend of number of research papers mentioning the theory.

Why only europium?

Europium has unique quality that Judd-Ofelt analysis can be done solely from the emission spectrum. For Judd-Ofelt of other elements from the absorption spectrum, look for the application software named RELIC.

How to use it?

All you need is the output file from the spectrofluorometer or a Origin file containing the spectrum intensity vs wavelength. The help file is contained within the application.

Application software

JOES is written in Java, and thus works on Windows, Linux or Mac OS. It is licensed under GPLv3. The application does not require installation. For Windows there are binaries available, for other platforms there are jar files.

What is the app capable for?

  • Calculate Branching ratios,

  • Calculate Radiative transition probabilities,

  • Calculate Cross-sections,

  • Calculate Barycenters,

  • Calculate Judd-Ofelt parameters

  • Calculate CIE color space coordinates

  • Estimate quantum efficiencies

  • Draw CIE diagram

  • Find Eu site symmetry

  • Contains Refractive index database of 150 materials

Simulator of Emission spectrum

Simulator of emission spectrum can be downloaded here. Two versions are available, a Mathematica notebook, and CDF file. CDF file can be opened with free Wolfram CDF player, but it cannot import spectrum. Mathematica notebook opens spectrum from spectrum.txt (placed at root, in MS Windows in C:\), for comparison with the simulated spectrum.

Example on the left is for Y2O3:Eu3+ doped with 3%.

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