Coherent Raman beat analysis of the hyperfine sublevel coherence properties of ¹⁶⁷Er³⁺ ions doped in an Y₂SiO₅ crystal

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• 作者：Daisuke Hashimoto ; Kaoru Shimizu ; ^{shimizu.kaoru@lab.ntt.co.jp" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Coherent Raman beat ; Hyperfine spectroscopy ; Sublevel coherence ; Coherence dissipation ; Er3+ ; YSO ; EIT
• 刊名：Journal of Luminescence
• 出版年：2016
• 出版时间：March 2016
• 年：2016
• 卷：171
• 期：Complete
• 页码：183-190
• 全文大小：1167 K

文摘

In this paper, we describe the use of coherent Raman beat (CRB) spectroscopy designed to reveal the phase coherence time t₂ of the ground state hyperfine sublevels of ¹⁶⁷Er³⁺ ions doped in an Y₂SiO₅ crystal cooled to a cryogenic temperature. The short optical coherence time T₂ (~1 μs) and sublevel population lifetime t₁ (~0.1 s) of the dopant Er³⁺ ions make it difficult to implement Raman echoes and optically detected spin echoes for measuring t₂, respectively. In contrast, CRB is insensitive to the T₂ and t₁ values and worth employing if we can cope with inhomogeneous dephasing. By comparing carefully with the effects of sublevel inhomogeneous broadening Δ₁₂ on the various Raman signals, we can estimate the t₂ value even when t₂>1/Δ₁₂. The ground-state t₂ values of the Λ-type three-level system identified in the ¹⁶⁷Er³⁺ ions are approximately 12 and 50 μs when the dopant concentrations are 0.005 and 0.001 at%, respectively. These t₂ values are long enough to realize electromagnetically induced transparency and coherent population trapping with an Er³⁺:Y₂SiO₅ crystal at a wavelength of 1.5 μm.