Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2101.08863 · Physical review. B./Physical review. B

Optical coherence and energy-level properties of a Tm3+ -doped LiNbO3 waveguide at subkelvin temperatures

Neil E. Sinclair, Daniel Oblak, Erhan Sağlamyürek, R. L. Cone, Charles W. Thiel, Wolfgang Tittel

Published Apr 12, 2021• 12 citations
arXivHTMLPDF

Abstract

We characterize the optical coherence and energy-level properties of the 795-nm $^{3}\mathrm{H}_{6}$ to $^{3}\mathrm{H}_{4}$ transition of ${\mathrm{Tm}}^{3+}$ in a ${\mathrm{Ti}}^{4+}$:$\mathrm{Li}\mathrm{Nb}{\mathrm{O}}_{3}$ waveguide at temperatures as low as 0.65 K. Coherence properties are measured with varied temperature, magnetic field, optical excitation power and wavelength, and measurement timescale. We also investigate nuclear spin-induced hyperfine structure and population dynamics with varying magnetic field and laser excitation power. Except for accountable differences due to different ${\mathrm{Ti}}^{4+}$- and ${\mathrm{Tm}}^{3+}$-doping concentrations, we find that the properties of ${\mathrm{Tm}}^{3+}$:${\mathrm{Ti}}^{4+}$:$\mathrm{Li}\mathrm{Nb}{\mathrm{O}}_{3}$ produced by indiffusion doping are consistent with those of a bulk-doped ${\mathrm{Tm}}^{3+}$:$\mathrm{Li}\mathrm{Nb}{\mathrm{O}}_{3}$ crystal measured under similar conditions. Our results, which complement previous work in a narrower parameter space, support using rare-earth ions for integrated optical and quantum signal processing.

DOI
10.1103/physrevb.103.134105

Related papers

Properties of a Rare-Earth-Ion-Doped Waveguide at Sub-Kelvin Temperatures for Quantum Signal Processing

Neil E. Sinclair, Daniel Oblak, Charles W. Thiel +2 more

We characterize the 795 nm ${^{3}\mathrm{H}}_{6}$ to ${^{3}\mathrm{H}}_{4}$ transition of ${\mathrm{Tm}}^{3+}$ in a ${\mathrm{Ti}}^{4+}:\mathrm{Li}\mathrm{Nb}{\mathrm{O}}_{3}$ waveguide at temperatures as low as 800 mK. Coherence and hyperfine population lifetimes---up to $117\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$ and 2.5 h, respectively---exceed those at 3 K at least tenfold, and are equivalent to those observed in a bulk ${\mathrm{Tm}}^{3+}:\mathrm{Li}\mathrm{Nb}{\mathrm{O}}_{3}$ crystal under similar conditions. We also find a transition dipole moment that is equivalent to that of the bulk. Finally, we prepare a 0.5 GHz-bandwidth atomic frequency comb of finesse $>2$ on a vanishing background. These results demonstrate the suitability of rare-earth-ion-doped waveguides created using industry-standard Ti indiffusion in $\mathrm{Li}\mathrm{Nb}{\mathrm{O}}_{3}$ for on-chip quantum applications.

arXiv:1605.02396•Physical Review Letters•Mar 7, 2017•43 citations

A rare-earth-ion-doped waveguide based on a standard photonics technology for quantum signal processing

Neil E. Sinclair, Daniel Oblak, Charles W. Thiel +2 more

We measure properties of the 795 nm $^3$H$_6$ to $^3$H$_4$ transition of a rare-earth-ion-doped waveguide, Tm$^{3+}$:Ti$^{4+}$:LiNbO$_{3}$, at temperatures as low as 800 mK. Coherence and hyperfine population lifetimes up to 117 $\mu$s and 2.5 hours, respectively, are observed. They are at least one order of magnitude greater than those measured at 3 K, and match those observed in a bulk Tm$^{3+}$:LiNbO$_{3}$ crystal under similar conditions. Furthermore, taking advantage of these properties, we prepare a 0.5 GHz-bandwidth atomic frequency comb quantum memory of finesse $>$2 on a vanishing background. Finally, we measure high Rabi frequencies and calculate a transition dipole moment of $\sim$10$^{-32}$ C$\cdot$m, which is equivalent to that of Tm$^{3+}$:LiNbO$_{3}$. Our results show the suitability of rare-earth-doped waveguides created using industry-standard Ti-indiffusion in LiNbO$_3$ for on-chip quantum applications.

•May 9, 2016•1 citation

Spectroscopy and Coherence of an Excited-State Transition in Tm$^{3+}$:YAlO$_3$ at Telecommunication Wavelength

Luozhen Li, Akshay Babu Karyath, Julien Bertrand +12 more

We characterize spectroscopic and coherence properties of the 1451.37 nm excited-state zero-phonon line (ZPL) between the $^{3}F_{4}$ and the $^{3}H_{4}$ manifolds of a thulium-doped yttrium aluminum perovskite (Tm$^{3+}$:YAlO$_3$) crystal at temperatures around 1.5 K. We measure the absorption spectrum between the $^{3}H_{6}$ - $^{3}F_{4}$ and $^{3}F_{4}$ - $^{3}H_{4}$ manifolds, the inhomogeneous broadening of the $^{3}F_{4}$ - $^{3}H_{4}$ (excited-state) ZPL, and the lifetimes of the higher-lying and lower-lying excited states. We also investigate level shifts caused by the quadratic Zeeman interaction as well as spectral hole-burning spectra with varying magnetic fields, providing insights into hyperfine interactions. Using again spectral holes but also optical free induction decays (FIDs), we assess optical coherence times, finding a maximum of $4.75 \pm 0.07~μs$ at B=2T and low ion concentration in the $^{3}F_{4}$ level. Our results -- the first to demonstrate coherence of an excited-state transition in a rare-earth crystal -- suggest the possibility of exploiting such transitions for quantum technology.

quant-pharXiv:2511.05370•Physical Review Research•Nov 10, 2025•0 citations

Optical decoherence studies of Tm3+:Y3Ga5O12

Charles W. Thiel, Neil E. Sinclair, Wolfgang Tittel +1 more

Decoherence of the 795 nm $^{3}\mathrm{H}{}_{6}$ to $^{3}\mathrm{H}{}_{4}$ transition in $1%{\mathrm{Tm}}^{3+}:{\mathrm{Y}}_{3}{\mathrm{Ga}}_{5}{\mathrm{O}}_{12}$ (Tm:YGG) is studied at temperatures as low as 1.2 K. The temperature, magnetic field, frequency, and time scale (spectral diffusion) dependence of the optical coherence lifetime is measured. Our results show that the coherence lifetime is impacted less by spectral diffusion than other known thulium-doped materials. Photon echo excitation and spectral hole burning methods reveal uniform decoherence properties and the possibility to produce full transparency for persistent spectral holes across the entire 56 GHz inhomogeneous bandwidth of the optical transition. Temperature-dependent decoherence is well described by elastic Raman scattering of phonons with an additional weaker component that may arise from a low density of glass-like dynamic disorder modes (two-level systems). Analysis of the observed behavior suggests that an optical coherence lifetime approaching 1 ms may be possible in this system at temperatures below 1 K for crystals grown with optimized properties. Overall, we find that Tm:YGG has superior decoherence properties compared to other Tm-doped crystals and is a promising candidate for applications that rely on long coherence lifetimes, such as optical quantum memories and photonic signal processing.

arXiv:1410.6096•Physical Review B•Dec 1, 2014•21 citations

Rare-earth-doped LiNbO3and KTiOPO4(KTP) for waveguide quantum memories

Charles W. Thiel, Yiwen Sun, R. M. Macfarlane +2 more

Optical waveguides in rare-earth-doped crystals are one of the most promising systems for practical implementations of quantum memory. To further develop these systems, detailed understanding of these materials is required. We report experimental studies of the optical properties and decoherence for Tm3+:LiNbO3, Pr3+:LiNbO3, Er3+:LiNbO3 and Er3+:KTiOPO4 (KTP) bulk crystals for quantum memory applications and discuss potential differences between the properties of the bulk single crystals and optical waveguides. These systems include the rare-earth ions most commonly exploited in quantum memory studies incorporated into two of the most technologically significant waveguide host materials. Photon echo methods were used to study decoherence as a function of temperature, applied magnetic field strength, dopant concentration and excitation wavelength. Decoherence mechanisms were investigated and modelled to interpret the observed behaviour. Spectral hole burning was used to characterize Stark and Zeeman effects. Bulk crystal properties were compared and contrasted to the properties of doped waveguides.

Journal of Physics B Atomic Molecular and Optical Physics•Jun 8, 2012•69 citations

Photon echo, spectral hole burning, and optically detected magnetic resonance in Yb 3 + 171 : LiNbO 3 bulk crystal and waveguides

F. Chiossi, Eloïse Lafitte-Houssat, Kangwei Xia +11 more

Recent progress in the realization of high-quality optical resonators and waveguides along with the possibility to incorporate rare-earth ions, make lithium niobate a promising material to build integrated platforms for quantum information processing. $^{171}\mathrm{Yb}^{3+}$ is a particularly attractive system because it can show long coherence lifetimes at zero magnetic field thanks to transitions insensitive to magnetic field fluctuations. In this paper, we investigate the optical and spin properties of $^{171}\mathrm{Yb}^{3+}$ ions in ${\mathrm{LiNbO}}_{3}$ bulk crystals as well as implanted waveguides. Using hole-burning spectroscopy and optically detected magnetic resonance, we studied ground and excited state hyperfine structures and probed optical and spin spectral holes. Importantly, the hole linewidths suggest that part of the ions in the waveguides are in a similar environment as in the bulk sample. We furthermore characterized spin population relaxation and coherence lifetimes of $^{171}\mathrm{Yb}^{3+}$ ions in the bulk crystal at temperatures between 50 mK and 9 K. At low temperatures, ${T}_{2}$ up to 9.5 $\ensuremath{\mu}\mathrm{s}$ (34 kHz homogeneous linewidth) and spin relaxation rates as long as $\ensuremath{\approx}100$ ms were measured. Our results show that $^{171}\mathrm{Yb}^{3+}$:$\mathrm{Li}\mathrm{Nb}{\mathrm{O}}_{3}$ is a system that exhibits narrow optical homogeneous linewidths over a 50 GHz bandwidth together with an electron spin degree of freedom. This is of interest for a variety of applications in integrated quantum photonics such as quantum memories or quantum processors.

Physical review. B./Physical review. B•May 31, 2022•7 citations
We characterize the optical coherence and energy-level properties of the 795-nm 3H6^{3}\mathrm{H}_{6}3H6​ to 3H4^{3}\mathrm{H}_{4}3H4​ transition of Tm3+{\mathrm{Tm}}^{3+}Tm3+ in a Ti4+{\mathrm{Ti}}^{4+}Ti4+:LiNbO3\mathrm{Li}\mathrm{Nb}{\mathrm{O}}_{3}LiNbO3​ waveguide at temperatures as low as 0.65 K. Coherence properties are measured with varied temperature, magnetic field, optical excitation power and wavelength, and measurement timescale. We also investigate nuclear spin-induced hyperfine structure and population dynamics with varying magnetic field and laser excitation power. Except for accountable differences due to different Ti4+{\mathrm{Ti}}^{4+}Ti4+- and Tm3+{\mathrm{Tm}}^{3+}Tm3+-doping concentrations, we find that the properties of Tm3+{\mathrm{Tm}}^{3+}Tm3+:Ti4+{\mathrm{Ti}}^{4+}Ti4+:LiNbO3\mathrm{Li}\mathrm{Nb}{\mathrm{O}}_{3}LiNbO3​ produced by indiffusion doping are consistent with those of a bulk-doped Tm3+{\mathrm{Tm}}^{3+}Tm3+:LiNbO3\mathrm{Li}\mathrm{Nb}{\mathrm{O}}_{3}LiNbO3​ crystal measured under similar conditions. Our results, which complement previous work in a narrower parameter space, support using rare-earth ions for integrated optical and quantum signal processing.
We characterize the 795 nm 3H6{^{3}\mathrm{H}}_{6}3H6​ to 3H4{^{3}\mathrm{H}}_{4}3H4​ transition of Tm3+{\mathrm{Tm}}^{3+}Tm3+ in a Ti4+:LiNbO3{\mathrm{Ti}}^{4+}:\mathrm{Li}\mathrm{Nb}{\mathrm{O}}_{3}Ti4+:LiNbO3​ waveguide at temperatures as low as 800 mK. Coherence and hyperfine population lifetimes---up to $117\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$ and 2.5 h, respectively---exceed those at 3 K at least tenfold, and are equivalent to those observed in a bulk Tm3+:LiNbO3{\mathrm{Tm}}^{3+}:\mathrm{Li}\mathrm{Nb}{\mathrm{O}}_{3}Tm3+:LiNbO3​ crystal under similar conditions. We also find a transition dipole moment that is equivalent to that of the bulk. Finally, we prepare a 0.5 GHz-bandwidth atomic frequency comb of finesse >2>2>2 on a vanishing background. These results demonstrate the suitability of rare-earth-ion-doped waveguides created using industry-standard Ti indiffusion in LiNbO3\mathrm{Li}\mathrm{Nb}{\mathrm{O}}_{3}LiNbO3​ for on-chip quantum applications.
We measure properties of the 795 nm 3^33H6_66​ to 3^33H4_44​ transition of a rare-earth-ion-doped waveguide, Tm3+^{3+}3+:Ti4+^{4+}4+:LiNbO3_{3}3​, at temperatures as low as 800 mK. Coherence and hyperfine population lifetimes up to 117 μ\muμs and 2.5 hours, respectively, are observed. They are at least one order of magnitude greater than those measured at 3 K, and match those observed in a bulk Tm3+^{3+}3+:LiNbO3_{3}3​ crystal under similar conditions. Furthermore, taking advantage of these properties, we prepare a 0.5 GHz-bandwidth atomic frequency comb quantum memory of finesse $>$2 on a vanishing background. Finally, we measure high Rabi frequencies and calculate a transition dipole moment of $\sim101010^{-32}$ C⋅\cdot⋅m, which is equivalent to that of Tm3+^{3+}3+:LiNbO3_{3}3​. Our results show the suitability of rare-earth-doped waveguides created using industry-standard Ti-indiffusion in LiNbO3_33​ for on-chip quantum applications.
Spectroscopy and Coherence of an Excited-State Transition in Tm3+^{3+}3+:YAlO3_33​ at Telecommunication Wavelength
We characterize spectroscopic and coherence properties of the 1451.37 nm excited-state zero-phonon line (ZPL) between the 3F4^{3}F_{4}3F4​ and the 3H4^{3}H_{4}3H4​ manifolds of a thulium-doped yttrium aluminum perovskite (Tm3+^{3+}3+:YAlO3_33​) crystal at temperatures around 1.5 K. We measure the absorption spectrum between the 3H6^{3}H_{6}3H6​ - 3F4^{3}F_{4}3F4​ and 3F4^{3}F_{4}3F4​ - 3H4^{3}H_{4}3H4​ manifolds, the inhomogeneous broadening of the 3F4^{3}F_{4}3F4​ - 3H4^{3}H_{4}3H4​ (excited-state) ZPL, and the lifetimes of the higher-lying and lower-lying excited states. We also investigate level shifts caused by the quadratic Zeeman interaction as well as spectral hole-burning spectra with varying magnetic fields, providing insights into hyperfine interactions. Using again spectral holes but also optical free induction decays (FIDs), we assess optical coherence times, finding a maximum of 4.75±0.07 μs4.75 \pm 0.07~μs4.75±0.07 μs at B=2T and low ion concentration in the 3F4^{3}F_{4}3F4​ level. Our results -- the first to demonstrate coherence of an excited-state transition in a rare-earth crystal -- suggest the possibility of exploiting such transitions for quantum technology.
Decoherence of the 795 nm 3H6^{3}\mathrm{H}{}_{6}3H6​ to 3H4^{3}\mathrm{H}{}_{4}3H4​ transition in 11%{\mathrm{Tm}}^{3+}:{\mathrm{Y}}_{3}{\mathrm{Ga}}_{5}{\mathrm{O}}_{12}1 (Tm:YGG) is studied at temperatures as low as 1.2 K. The temperature, magnetic field, frequency, and time scale (spectral diffusion) dependence of the optical coherence lifetime is measured. Our results show that the coherence lifetime is impacted less by spectral diffusion than other known thulium-doped materials. Photon echo excitation and spectral hole burning methods reveal uniform decoherence properties and the possibility to produce full transparency for persistent spectral holes across the entire 56 GHz inhomogeneous bandwidth of the optical transition. Temperature-dependent decoherence is well described by elastic Raman scattering of phonons with an additional weaker component that may arise from a low density of glass-like dynamic disorder modes (two-level systems). Analysis of the observed behavior suggests that an optical coherence lifetime approaching 1 ms may be possible in this system at temperatures below 1 K for crystals grown with optimized properties. Overall, we find that Tm:YGG has superior decoherence properties compared to other Tm-doped crystals and is a promising candidate for applications that rely on long coherence lifetimes, such as optical quantum memories and photonic signal processing.
Optical waveguides in rare-earth-doped crystals are one of the most promising systems for practical implementations of quantum memory. To further develop these systems, detailed understanding of these materials is required. We report experimental studies of the optical properties and decoherence for Tm3+:LiNbO3, Pr3+:LiNbO3, Er3+:LiNbO3 and Er3+:KTiOPO4 (KTP) bulk crystals for quantum memory applications and discuss potential differences between the properties of the bulk single crystals and optical waveguides. These systems include the rare-earth ions most commonly exploited in quantum memory studies incorporated into two of the most technologically significant waveguide host materials. Photon echo methods were used to study decoherence as a function of temperature, applied magnetic field strength, dopant concentration and excitation wavelength. Decoherence mechanisms were investigated and modelled to interpret the observed behaviour. Spectral hole burning was used to characterize Stark and Zeeman effects. Bulk crystal properties were compared and contrasted to the properties of doped waveguides.
Recent progress in the realization of high-quality optical resonators and waveguides along with the possibility to incorporate rare-earth ions, make lithium niobate a promising material to build integrated platforms for quantum information processing. 171Yb3+^{171}\mathrm{Yb}^{3+}171Yb3+ is a particularly attractive system because it can show long coherence lifetimes at zero magnetic field thanks to transitions insensitive to magnetic field fluctuations. In this paper, we investigate the optical and spin properties of 171Yb3+^{171}\mathrm{Yb}^{3+}171Yb3+ ions in LiNbO3{\mathrm{LiNbO}}_{3}LiNbO3​ bulk crystals as well as implanted waveguides. Using hole-burning spectroscopy and optically detected magnetic resonance, we studied ground and excited state hyperfine structures and probed optical and spin spectral holes. Importantly, the hole linewidths suggest that part of the ions in the waveguides are in a similar environment as in the bulk sample. We furthermore characterized spin population relaxation and coherence lifetimes of 171Yb3+^{171}\mathrm{Yb}^{3+}171Yb3+ ions in the bulk crystal at temperatures between 50 mK and 9 K. At low temperatures, T2{T}_{2}T2​ up to 9.5 $\ensuremath{\mu}\mathrm{s}$ (34 kHz homogeneous linewidth) and spin relaxation rates as long as $\ensuremath{\approx}100$ ms were measured. Our results show that 171Yb3+^{171}\mathrm{Yb}^{3+}171Yb3+:LiNbO3\mathrm{Li}\mathrm{Nb}{\mathrm{O}}_{3}LiNbO3​ is a system that exhibits narrow optical homogeneous linewidths over a 50 GHz bandwidth together with an electron spin degree of freedom. This is of interest for a variety of applications in integrated quantum photonics such as quantum memories or quantum processors.