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

Journal of Optics

Optical characterizations of densely doped Tm3+:KYW crystals at low temperatures

Yisheng Lei, Trevor Kling, Mahdi Hosseini

Published Jul 8, 2024• 0 citations
Publisher

Abstract

Abstract We investigate the optical lifetime, decay characteristics, spectral linewidth and energy level properties of thulium ions doped in a KY(WO 4 ) 2 crystal at 4 K temperature. High doping concentration of thulium ions with inhomogeneous broadening allow us to study nonradiative behaviors, instantaneous spectral diffusion, and spectral power broadening in this solid-state material. The theoretical consideration of ion–ion interactions is shown to accurately characterize the absorption, decay and other spectral behaviors of Tm 3 + ions. We observe more than ten-fold reduction in the decay time of 3H4 state and about three-fold reduction in the spectral-hole lifetime as we approach the center of the inhomogeneous broadening, corresponding to higher optical densities.

DOI
10.1088/2040-8986/ad6010

Related papers

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

Optical investigations of coherence and relaxation dynamics of a thulium-doped yttrium gallium garnet crystal at sub-kelvin temperatures for optical quantum memory

Antariksha Das, Mohsen Falamarzi Askarani, Jacob H. Davidson +7 more

Abstract Rare-earth ion-doped crystals are of great interest for quantum memories, a central component in future quantum repeaters. To assess the promise of 1 % Tm3+-doped yttrium gallium garnet (Tm:YGG), we report measurements of optical coherence and energy-level lifetimes of its 3H 6 ↔ 3 H4 transition at a temperature of around 500 mK and various magnetic fields. Using spectral hole burning (SHB), we find hyperfine ground-level (Zeeman level) lifetimes of several minutes at magnetic fields of less than 1000 G. We also measure coherence time exceeding one millisecond using two-pulse photon echoes. Three-pulse photon echo and SHB measurements reveal that due to spectral diffusion, the effective coherence time reduces to a few µs over a timescale of around two hundred seconds. Finally, temporal and frequency-multiplexed storage of optical pulses using the atomic frequency comb protocol is demonstrated. Our results suggest Tm:YGG to be promising for multiplexed photonic quantum memory for quantum repeaters.

arXiv:2406.08167•Materials for Quantum Technology•Jul 18, 2024•3 citations

Concentration dependence of absorption and optical and hyperfine transition dynamics in Pr 3 + :La 2 (WO 4 ) 3

Florian Beaudoux, O. Guillot-Noël, Julien Lejay +2 more

Optical and hyperfine parameters of the 3H4–1D2 transition are investigated in Pr3 +:La2(WO4)3 for doping concentrations ranging from 0.02 to 3 at.%, at liquid helium temperatures. This includes optical inhomogeneous and homogeneous linewidths, peak absorption, excited-state population decays, spectral hole lifetime and inhomogeneous and homogeneous hyperfine linewidths. Optical inhomogeneous broadening with increasing Pr3 + concentration is limited due to close atomic radii between Pr3 + and La3 +. The peak absorption coefficient increases with increasing Pr3 + doping, reaching up to 28 cm−1. At the highest Pr3 + concentration, optical coherence lifetime is 4.6 μs and hole lifetime 2 s, which should allow one to transfer coherences and tailor the optical inhomogeneous linewidth, as required for rare earth-based optical quantum memories. Raman echo experiments show that hyperfine inhomogeneous linewidth and coherence lifetime (50 kHz and 250 μs respectively) are independent of Pr3 + concentration. These results suggest that highly doped crystals are useful for efficient and long-storage time quantum memories.

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

Investigations of spectral dynamics in rare earth ion doped crystals using high resolution laser techniques

Graf, Felix R.

Solids containing rare earth (RE) ions have attracted spectroscopists' attention since the beginning of this century.In the last 30 years, their extremely narrow spectral features in combination with the use of non linear spectroscopy have served to sensitively measure ion-solid interactions and to progressively observe narrower homogeneous linewidths.The potential for using RE ion doped crystals as optical storage materials and processors has lately been a driving force in their investigations, Here, the ratio of inhomogeneous to homogeneous linewidth is regarded as an adequate measure of storage density and can become as big as 10 7 at cryogenic temperatures.Therefore, the analysis of line broadening is of fundamental as well as applied interest.This work is concerned with the investigation of interactions of RE ions with their environment.By means of a laser with a kilohertz resolution and non-linear spectroscopy, spectral dynamics as a function of intrinsic, external electric field, or light-pulse induced perturbations are analyzed on different time scales.In the first part, the theoretical background for the spectroscopy of RE ion doped crystals is outlined.The energy levels are presented and it is shown that due to their electronic properties RE ions have spectrally narrow electronic transitions, sometimes in the sub-kHz regime.The investigations of these narrow spectral features on the seconds to minutes time scale require very stable tunable laser sources.At present, such devices are not commercially available.In the second part, the performance of ahorne built laser system is characterized using persistent spectral holes, The results show that frequency selective materials can be used as powerful tools for the high resolution Vlll Abstract spectral analysis of laser sources.Complementary to that, they give a measure for the long term evolution of the spectral holes for the particular hole burning substance.In the third part, the effect of an external electric field on RE ion doped crystals is investigated.It is shown that for these systems the electric field induced frequency shifts are fully reversible.A general theory of Stark splittings of RE doped crystals is introduced and two methods are presented which allow for the determination of the magnitude and orientation of the electric dipole moment differences with sub-degree accuracy.Finally in the last part, spectral line broadening mechanisms of RE ion doped crystals are discussed and investigated by means of two-pulse photon echoes.Through variation of the experimental parameters, a discrimination between the different contributions is partly achieved and characteristic properties for different dephasing mechanisms are presented.In combination with the measurements from the third part, quantitative predictions of the electric dipole-dipole induced broadening are carried out, which are compared to the experimental results,

•Jan 1, 1998•5 citations

Slow light using spectral hole burning in a Tm3+ -doped yttrium-aluminum-garnet crystal

Romain Lauro, T. Chanelière, J.-L. Le Gouët

We report on light slowing down in a rare-earth-metal-ion-doped crystal by persistent spectral hole burning. The absence of motion of the active ions, the large inhomogeneous broadening, the small homogeneous width, and the long lifetime of the hyperfine shelving states make this material convenient for the burning of narrow persistent spectral holes. Since the hole can be burnt long before the arrival of the input signal, there is no need for a strong-coupling field, illuminating the sample simultaneously with the input signal, in contrast with procedures such as electromagnetically induced transparency or coherent population oscillations. Analyzing the slowing down process, we point out the role played by the off-resonant atom. Most of the incoming information is carried over to off-resonant atoms, while the pulse is confined within the sample. The observed speed-of-light reduction factor exceeds ${10}^{5}$.

Physical Review A•Jun 30, 2009•29 citations
Abstract We investigate the optical lifetime, decay characteristics, spectral linewidth and energy level properties of thulium ions doped in a KY(WO 4 ) 2 crystal at 4 K temperature. High doping concentration of thulium ions with inhomogeneous broadening allow us to study nonradiative behaviors, instantaneous spectral diffusion, and spectral power broadening in this solid-state material. The theoretical consideration of ion–ion interactions is shown to accurately characterize the absorption, decay and other spectral behaviors of Tm 3 + ions. We observe more than ten-fold reduction in the decay time of 3H4 state and about three-fold reduction in the spectral-hole lifetime as we approach the center of the inhomogeneous broadening, corresponding to higher optical densities.
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.
Abstract Rare-earth ion-doped crystals are of great interest for quantum memories, a central component in future quantum repeaters. To assess the promise of 1 % Tm3+-doped yttrium gallium garnet (Tm:YGG), we report measurements of optical coherence and energy-level lifetimes of its 3H 6 ↔ 3 H4 transition at a temperature of around 500 mK and various magnetic fields. Using spectral hole burning (SHB), we find hyperfine ground-level (Zeeman level) lifetimes of several minutes at magnetic fields of less than 1000 G. We also measure coherence time exceeding one millisecond using two-pulse photon echoes. Three-pulse photon echo and SHB measurements reveal that due to spectral diffusion, the effective coherence time reduces to a few µs over a timescale of around two hundred seconds. Finally, temporal and frequency-multiplexed storage of optical pulses using the atomic frequency comb protocol is demonstrated. Our results suggest Tm:YGG to be promising for multiplexed photonic quantum memory for quantum repeaters.
Optical and hyperfine parameters of the 3H4–1D2 transition are investigated in Pr3 +:La2(WO4)3 for doping concentrations ranging from 0.02 to 3 at.%, at liquid helium temperatures. This includes optical inhomogeneous and homogeneous linewidths, peak absorption, excited-state population decays, spectral hole lifetime and inhomogeneous and homogeneous hyperfine linewidths. Optical inhomogeneous broadening with increasing Pr3 + concentration is limited due to close atomic radii between Pr3 + and La3 +. The peak absorption coefficient increases with increasing Pr3 + doping, reaching up to 28 cm−1. At the highest Pr3 + concentration, optical coherence lifetime is 4.6 μs and hole lifetime 2 s, which should allow one to transfer coherences and tailor the optical inhomogeneous linewidth, as required for rare earth-based optical quantum memories. Raman echo experiments show that hyperfine inhomogeneous linewidth and coherence lifetime (50 kHz and 250 μs respectively) are independent of Pr3 + concentration. These results suggest that highly doped crystals are useful for efficient and long-storage time quantum memories.
Solids containing rare earth (RE) ions have attracted spectroscopists' attention since the beginning of this century.In the last 30 years, their extremely narrow spectral features in combination with the use of non linear spectroscopy have served to sensitively measure ion-solid interactions and to progressively observe narrower homogeneous linewidths.The potential for using RE ion doped crystals as optical storage materials and processors has lately been a driving force in their investigations, Here, the ratio of inhomogeneous to homogeneous linewidth is regarded as an adequate measure of storage density and can become as big as 10 7 at cryogenic temperatures.Therefore, the analysis of line broadening is of fundamental as well as applied interest.This work is concerned with the investigation of interactions of RE ions with their environment.By means of a laser with a kilohertz resolution and non-linear spectroscopy, spectral dynamics as a function of intrinsic, external electric field, or light-pulse induced perturbations are analyzed on different time scales.In the first part, the theoretical background for the spectroscopy of RE ion doped crystals is outlined.The energy levels are presented and it is shown that due to their electronic properties RE ions have spectrally narrow electronic transitions, sometimes in the sub-kHz regime.The investigations of these narrow spectral features on the seconds to minutes time scale require very stable tunable laser sources.At present, such devices are not commercially available.In the second part, the performance of ahorne built laser system is characterized using persistent spectral holes, The results show that frequency selective materials can be used as powerful tools for the high resolution Vlll Abstract spectral analysis of laser sources.Complementary to that, they give a measure for the long term evolution of the spectral holes for the particular hole burning substance.In the third part, the effect of an external electric field on RE ion doped crystals is investigated.It is shown that for these systems the electric field induced frequency shifts are fully reversible.A general theory of Stark splittings of RE doped crystals is introduced and two methods are presented which allow for the determination of the magnitude and orientation of the electric dipole moment differences with sub-degree accuracy.Finally in the last part, spectral line broadening mechanisms of RE ion doped crystals are discussed and investigated by means of two-pulse photon echoes.Through variation of the experimental parameters, a discrimination between the different contributions is partly achieved and characteristic properties for different dephasing mechanisms are presented.In combination with the measurements from the third part, quantitative predictions of the electric dipole-dipole induced broadening are carried out, which are compared to the experimental results,
We report on light slowing down in a rare-earth-metal-ion-doped crystal by persistent spectral hole burning. The absence of motion of the active ions, the large inhomogeneous broadening, the small homogeneous width, and the long lifetime of the hyperfine shelving states make this material convenient for the burning of narrow persistent spectral holes. Since the hole can be burnt long before the arrival of the input signal, there is no need for a strong-coupling field, illuminating the sample simultaneously with the input signal, in contrast with procedures such as electromagnetically induced transparency or coherent population oscillations. Analyzing the slowing down process, we point out the role played by the off-resonant atom. Most of the incoming information is carried over to off-resonant atoms, while the pulse is confined within the sample. The observed speed-of-light reduction factor exceeds 105{10}^{5}105.