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arXiv · 2409.15622

Spectroscopy, Crystal-Field, and Transition Intensity Analyses of the C$_{\rm 3v}$(O$^{2-}$) Centre in Er$^{3+}$ Doped CaF$_{2}$ Crystals

M. D. Moull·J. B. L. Martin·T. G. M. Newman·A. L. Jeffery·J. G. Bartholomew·J. -P. R. Wells·M. F. Reid
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Abstract

Erbium ions in crystals show considerable promise for the technologies that will form the backbone of future networked quantum information technology. Despite advances in leveraging erbium's fibre-compatible infrared transition for classical and quantum applications, the transitions are, in general, not well understood. We present detailed absorption and laser site-selective spectroscopy of the C$_{\rm 3v}$(O$^{2-}$) centre in CaF$_2$:Er$^{3+}$ as an interesting erbium site case study. The $^{4}$I$_{15/2}$Z$_1 \rightarrow {^{4}}$I$_{13/2}$Y$_1$ transition has a low-temperature inhomogeneous linewidth of 1 GHz with hyperfine structure observable from the $^{167}$Er isotope. A parametrized crystal-field Hamiltonian is fitted to 34 energy levels and the two ground state magnetic splitting factors. The wavefunctions are used to perform a transition intensity analysis and electric-dipole parameters are fitted to absorption oscillator strengths. Simulated spectra for the $^{4}$I$_{11/2}\rightarrow {^{4}}$I$_{15/2}$ and $^{4}$I$_{13/2} \rightarrow {^{4}}$I$_{15/2}$ inter-multiplet transitions are in excellent agreement with the experimentally measured spectra. The $^{4}$I$_{13/2}$ excited state lifetime is 25.0\,ms and the intensity calculation is in excellent agreement with this value.

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M. D. Moull, J. B. L. Martin, T. G. M. Newman, A. L. Jeffery, J. G. Bartholomew, J. -P. R. Wells, M. F. Reid. 2024-09-23. Spectroscopy, Crystal-Field, and Transition Intensity Analyses of the C$_{\rm 3v}$(O$^{2-}$) Centre in Er$^{3+}$ Doped CaF$_{2}$ Crystals. https://arxiv.org/abs/2409.15622

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