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

Applied Sciences

Investigation of Population Dynamics in 1.54-μm Telecom Transitions of Epitaxial (ErxSc1-x)2O3 Thin Layers for Coherent Population Manipulation: Weak Excitation Regime

S. Adachi, Yoshihiro Kawakami, Reina Kaji, Takehiko Tawara, Hiroo Omi

Published May 25, 2018• 3 citations
Publisher

Abstract

We have investigated the energy transfers in the 1.54- μ m region of (Er,Sc) 2 O 3 epitaxial thin films grown on Si(111). The interplay of the energy transfers between Er ions in the different and the same symmetry sites makes the dynamics complicated. To suppress the energy transfer upconversion, low power and resonant excitation of the third crystal-field level ( 4 I 13 / 2 : Y 3 ′ ) of the Er 3 + site with C 3 i symmetry was employed. The time-resolved photoluminescence measurements of the Y 1 ′ - Z 1 ′ transition indicate the existence of two decay components having fast (10–100 μ s) and slow (0.1–1 ms) relaxation times in the range of 4–60 K. The model calculation including the inter-site energy transfers, the temperature-sensitive and -insensitive non-radiative relaxations fits the experimental results well. Moreover, the long averaged inter-Er 3 + distance obtained by decreasing Er concentration was found to reduce two kinds of non-radiative relaxation rates and the energy transfer rates between Er ions very effectively.

DOI
10.3390/app8060874

Related papers

Population dynamics in epitaxial Er2O3 thin films grown on Si(111)

Takehiko Tawara, Hiroo Omi, T. Hozumi +4 more

We grow single crystal erbium-oxide (Er2O3) epitaxially on a Si (111) substrate by using molecular beam epitaxy and investigate the population dynamics in Er3+ ions for the coherent manipulation of the population in Er2O3. Sharp and discrete Stark energy levels of the 4I13/2 manifold as small as 200 μeV are observed with inhomogeneous broadening caused by the uniform crystal field of the epitaxial Er2O3. We also experimentally determine the time constant of the resonant population transfer between spatially distant Er3+-ion sites, which is limited to the manipulation time of the population in the Er2O3 crystals. Using selective excitation of the Stark level in the 4I13/2 manifold, we obtain the energy transfer times between spatially distant Er3+ ions, and they are about 2 μs between sites whose crystallographic symmetry is different and 10 μs between sites whose symmetry is the same.

Applied Physics Letters•Jun 17, 2013•22 citations

Energy transfer in epitaxial Er2O3 thin films grown on Si(111) substrates

Takehiko Tawara, T. Hozumi, Hiroo Omi +4 more

Time constants of a resonant energy transfer between Er ions in epitaxial Er2O3grown on Si(111) are investigated for the coherent manipulation of populations and experimentally estimated to be several microseconds by resonant excitation photoluminescence.

IEEE Photonics Conference•Sep 1, 2013•0 citations

Epitaxial Er-doped Y2O3 on silicon for quantum coherent devices

Manish Kumar Singh, Abhinav Prakash, Gary Wolfowicz +6 more

Rare-earth ions (REIs) have incomplete 4f shells and possess narrow optical intra-4f transitions due to shielding from electrons in the 5s and 5p orbitals, making them good candidates for solid-state optical quantum memory. The emission of Er3+ in the telecom C-band (1530 nm–1565 nm) makes it especially attractive for this application. In order to build practical, scalable devices, the REI needs to be embedded in a non-interacting host material, preferably one that can be integrated with silicon. In this paper, we show that Er3+ can be isovalently incorporated into epitaxial Y2O3 thin films on Si (111). We report on the synthesis of epitaxial, single-crystalline Er:Y2O3 on Si with a narrow inhomogeneous linewidth in the photoluminescence (PL) spectra, 5.1 GHz (<100 mK), and an optical excited state lifetime of 8.1 ms. The choice of Y2O3 was driven by its low nuclear spin and small lattice mismatch with Si. Using PL and electron paramagnetic resonance, we show that Er3+ substitutes for Y in the crystal lattice. The role of interfacial SiOx, diffusion of silicon into the film, and the effect of buffer layers on the inhomogeneous PL linewidth are examined. We also find that the linewidth decreased monotonically with film thickness but surprisingly exhibits no correlation with the film crystalline quality, as measured by the x-ray rocking curve scans, suggesting other factors at play that limit the inhomogeneous broadening in Y2O3 films.

APL Materials•Mar 1, 2020•56 citations

A Pathway to Er Sites in Si with Long Spin and Optical Coherence Times

Alexey Lyasota, Ian R. Berkman, Gabriele G. de Boo +9 more

Rare-earth ions in solid-state hosts exhibit low homogeneous broadening and long spin coherence at cryogenic temperatures thus making them a promising candidate for optical quantum memories [1], optical-microwave transducers [2] and single dopant-based devices such as single photon emitters operating at the telecommunication wavelengths [3]. Here, we present an overview of the spin and optical properties of Er ensembles in Si accessed via resonant photoluminescence excitation (PLE) spectroscopy [4]. Samples were positioned directly on top of tailor-fabricated superconducting single photon detectors, placed in a dilution refrigerator unit and resonantly excited using fiber optics. Our method provided high collection efficiency and allowed spectral measurements of low Er density samples. The observed Er PLE spectra were strongly affected by the presence of co-dopants such as O, B or P reflecting their influence on the formation of optically active Er sites and corresponding Er optical transition energies. Higher O densities resulted in especially rich PLE spectra suggesting that a variety of Er-O complexes formed due to O doping. Lowering the O concentration, we achieved PLE spectra dominated by a single Er site in P doped samples. Interestingly, the Er spin relaxation and optical coherence properties were barely affected by the employed co-dopants and mainly depended on the Er concentration. By lowering the Er concentration from relatively high (1018cm-3) to low densities (1016cm-3), we were able to increase Er spin lifetimes from ~0.1 s to ~30 s. Long spin relaxation times allowed us to identify PLE spectra of new Er sites in Si. In both concentration regimes, we observed sub-MHz transient spectral holes suggesting long optical coherence times. Furthermore, we observed sub-MHz spin transitions in both natural and isotopically purified Si and achieved spin coherence times above 1 ms in isotopically purified Si. Narrow optical linewidths and long transverse and longitudinal spin relaxation times show that Er in Si is an excellent candidate for future quantum information and communication applications.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jun 26, 2023•0 citations

Phonon-mediated temperature dependence of Er3+ optical transitions in Er2O3

Adam Dodson, Hongrui Wu, Anuruddh Rai +14 more

Abstract Characterization of the atomic level processes that determine optical transitions in emerging materials is critical to the development of new platforms for classical and quantum networking. Such understanding often emerges from studies of the temperature dependence of the transitions. We report measurements of the temperature dependent Er 3+ photoluminescence in single crystal Er 2 O 3 thin films epitaxially grown on Si(111) focused on transitions that involve the closely spaced Stark-split levels. Radiative intensities are compared to a model that includes relevant Stark-split states, single phonon-assisted excitations, and the well-established level population redistribution due to thermalization. This approach, applied to the individual Stark-split states and employing Er 2 O 3 specific single-phonon-assisted excitations, gives good agreement with experiment. This model allows us to demonstrate the difference in the electron-phonon coupling of the 4 S 3/2 and 2 H 11/2 states of Er 3+ in E 2 O 3 and suggests that the temperature dependence of Er 3+ emission intensity may vary significantly with small shifts in the wavelength (~0.1 nm) of the excitation source.

Communications Physics•Feb 28, 2024•10 citations

Investigation of Non-linear Energy Transfer Dynamics of Erbium in Yttrium Aluminum Garnet

Christian Vega

Yttrium Aluminum Garnet (YAG, Y_3 〖Al〗_5 O_12) crystals doped with Erbium have posed an interesting position in the field of rare earth solid state lasers as they possess the property of self-saturation, in which the upper energy level in a laser has a much shorter lifetime than that of the lower level. This is the case of the 2.94μm transition in Er:YAG. That property at first seems to make this material unfit for use as a laser gain medium, however further research into these classes of rare earth materials revealed interesting non-liner energy transfer mechanisms that allow it to be a useful mid wave infra-red (MWIR) coherent source in the continuous wave (CW) and pulsed regimes. This came to fruition due to decades of modeling and spectroscopic research investigating the non-linear energy transfer mechanisms of excited state absorption (ESA), energy transfer up-conversion (ETU), and cross relaxation (XR). These effects show up in the rise and fall times of the levels observed through fluorescence. Resulting in the non-exponential rise and fall characteristics and having a squared or even cubed relation to the population. The population evolution for each of the lasing levels is now affected by ions recycling energy and in turn cause the lifetimes of the levels to “effectively” change to a point where simple linear models do not adequately describe the system and its performance. The non-linear energy transfer dynamics of Er:YAG are modeled under high resonant pump conditions. By pumping with selective resonant pumps, the interaction dynamics of the (_ ^4)I_(11/2) and the (_ ^4)I_(13/2) levels in the Erbium ion reveal the contributions from generally ignored non-linear energy transfer mechanisms. Specifically, the multi-photon effect known as excited state absorption (ESA) is modeled by measuring and characterizing the cross section in single crystal Er:YAG samples utilizing a pump and probe technique coupled with transient fluorescence measurements. The measured ESA cross section is then included in the rate equation modeling.

•Jan 1, 2018•0 citations
We have investigated the energy transfers in the 1.54- μ m region of (Er,Sc) 2 O 3 epitaxial thin films grown on Si(111). The interplay of the energy transfers between Er ions in the different and the same symmetry sites makes the dynamics complicated. To suppress the energy transfer upconversion, low power and resonant excitation of the third crystal-field level ( 4 I 13 / 2 : Y 3 ′ ) of the Er 3 + site with C 3 i symmetry was employed. The time-resolved photoluminescence measurements of the Y 1 ′ - Z 1 ′ transition indicate the existence of two decay components having fast (10–100 μ s) and slow (0.1–1 ms) relaxation times in the range of 4–60 K. The model calculation including the inter-site energy transfers, the temperature-sensitive and -insensitive non-radiative relaxations fits the experimental results well. Moreover, the long averaged inter-Er 3 + distance obtained by decreasing Er concentration was found to reduce two kinds of non-radiative relaxation rates and the energy transfer rates between Er ions very effectively.
We grow single crystal erbium-oxide (Er2O3) epitaxially on a Si (111) substrate by using molecular beam epitaxy and investigate the population dynamics in Er3+ ions for the coherent manipulation of the population in Er2O3. Sharp and discrete Stark energy levels of the 4I13/2 manifold as small as 200 μeV are observed with inhomogeneous broadening caused by the uniform crystal field of the epitaxial Er2O3. We also experimentally determine the time constant of the resonant population transfer between spatially distant Er3+-ion sites, which is limited to the manipulation time of the population in the Er2O3 crystals. Using selective excitation of the Stark level in the 4I13/2 manifold, we obtain the energy transfer times between spatially distant Er3+ ions, and they are about 2 μs between sites whose crystallographic symmetry is different and 10 μs between sites whose symmetry is the same.
Rare-earth ions (REIs) have incomplete 4f shells and possess narrow optical intra-4f transitions due to shielding from electrons in the 5s and 5p orbitals, making them good candidates for solid-state optical quantum memory. The emission of Er3+ in the telecom C-band (1530 nm–1565 nm) makes it especially attractive for this application. In order to build practical, scalable devices, the REI needs to be embedded in a non-interacting host material, preferably one that can be integrated with silicon. In this paper, we show that Er3+ can be isovalently incorporated into epitaxial Y2O3 thin films on Si (111). We report on the synthesis of epitaxial, single-crystalline Er:Y2O3 on Si with a narrow inhomogeneous linewidth in the photoluminescence (PL) spectra, 5.1 GHz (<100 mK), and an optical excited state lifetime of 8.1 ms. The choice of Y2O3 was driven by its low nuclear spin and small lattice mismatch with Si. Using PL and electron paramagnetic resonance, we show that Er3+ substitutes for Y in the crystal lattice. The role of interfacial SiOx, diffusion of silicon into the film, and the effect of buffer layers on the inhomogeneous PL linewidth are examined. We also find that the linewidth decreased monotonically with film thickness but surprisingly exhibits no correlation with the film crystalline quality, as measured by the x-ray rocking curve scans, suggesting other factors at play that limit the inhomogeneous broadening in Y2O3 films.
Rare-earth ions in solid-state hosts exhibit low homogeneous broadening and long spin coherence at cryogenic temperatures thus making them a promising candidate for optical quantum memories [1], optical-microwave transducers [2] and single dopant-based devices such as single photon emitters operating at the telecommunication wavelengths [3]. Here, we present an overview of the spin and optical properties of Er ensembles in Si accessed via resonant photoluminescence excitation (PLE) spectroscopy [4]. Samples were positioned directly on top of tailor-fabricated superconducting single photon detectors, placed in a dilution refrigerator unit and resonantly excited using fiber optics. Our method provided high collection efficiency and allowed spectral measurements of low Er density samples. The observed Er PLE spectra were strongly affected by the presence of co-dopants such as O, B or P reflecting their influence on the formation of optically active Er sites and corresponding Er optical transition energies. Higher O densities resulted in especially rich PLE spectra suggesting that a variety of Er-O complexes formed due to O doping. Lowering the O concentration, we achieved PLE spectra dominated by a single Er site in P doped samples. Interestingly, the Er spin relaxation and optical coherence properties were barely affected by the employed co-dopants and mainly depended on the Er concentration. By lowering the Er concentration from relatively high (1018cm-3) to low densities (1016cm-3), we were able to increase Er spin lifetimes from ~0.1 s to ~30 s. Long spin relaxation times allowed us to identify PLE spectra of new Er sites in Si. In both concentration regimes, we observed sub-MHz transient spectral holes suggesting long optical coherence times. Furthermore, we observed sub-MHz spin transitions in both natural and isotopically purified Si and achieved spin coherence times above 1 ms in isotopically purified Si. Narrow optical linewidths and long transverse and longitudinal spin relaxation times show that Er in Si is an excellent candidate for future quantum information and communication applications.
Abstract Characterization of the atomic level processes that determine optical transitions in emerging materials is critical to the development of new platforms for classical and quantum networking. Such understanding often emerges from studies of the temperature dependence of the transitions. We report measurements of the temperature dependent Er 3+ photoluminescence in single crystal Er 2 O 3 thin films epitaxially grown on Si(111) focused on transitions that involve the closely spaced Stark-split levels. Radiative intensities are compared to a model that includes relevant Stark-split states, single phonon-assisted excitations, and the well-established level population redistribution due to thermalization. This approach, applied to the individual Stark-split states and employing Er 2 O 3 specific single-phonon-assisted excitations, gives good agreement with experiment. This model allows us to demonstrate the difference in the electron-phonon coupling of the 4 S 3/2 and 2 H 11/2 states of Er 3+ in E 2 O 3 and suggests that the temperature dependence of Er 3+ emission intensity may vary significantly with small shifts in the wavelength (~0.1 nm) of the excitation source.
Yttrium Aluminum Garnet (YAG, Y_3 〖Al〗_5 O_12) crystals doped with Erbium have posed an interesting position in the field of rare earth solid state lasers as they possess the property of self-saturation, in which the upper energy level in a laser has a much shorter lifetime than that of the lower level. This is the case of the 2.94μm transition in Er:YAG. That property at first seems to make this material unfit for use as a laser gain medium, however further research into these classes of rare earth materials revealed interesting non-liner energy transfer mechanisms that allow it to be a useful mid wave infra-red (MWIR) coherent source in the continuous wave (CW) and pulsed regimes. This came to fruition due to decades of modeling and spectroscopic research investigating the non-linear energy transfer mechanisms of excited state absorption (ESA), energy transfer up-conversion (ETU), and cross relaxation (XR). These effects show up in the rise and fall times of the levels observed through fluorescence. Resulting in the non-exponential rise and fall characteristics and having a squared or even cubed relation to the population. The population evolution for each of the lasing levels is now affected by ions recycling energy and in turn cause the lifetimes of the levels to “effectively” change to a point where simple linear models do not adequately describe the system and its performance. The non-linear energy transfer dynamics of Er:YAG are modeled under high resonant pump conditions. By pumping with selective resonant pumps, the interaction dynamics of the (_ ^4)I_(11/2) and the (_ ^4)I_(13/2) levels in the Erbium ion reveal the contributions from generally ignored non-linear energy transfer mechanisms. Specifically, the multi-photon effect known as excited state absorption (ESA) is modeled by measuring and characterizing the cross section in single crystal Er:YAG samples utilizing a pump and probe technique coupled with transient fluorescence measurements. The measured ESA cross section is then included in the rate equation modeling.