Optics Letters

Spin-lattice relaxation by the direct process in optically excited Er^3+ in LaF_3

H. Wolfrum, K. Lanzinger, Karl Friedrich Renk

Published Jul 1, 1980• 10 citations

Abstract

Spin-lattice relaxation within the lower Stark component of the metastable 4S3 /2 state of Er3+ ions in LaF3 has been studied by an optical method at high magnetic fields B and at low crystal temperature. The relaxation rate increases as B5, as expected for a direct-process relaxation within Kramers doublets at large Zeeman splittings.

DOI: 10.1364/ol.5.000294

Related papers

Spin-lattice relaxation in the excited ^4S_3/2 state of Er^3+ in LaF_3

Matthijs M. Broer, John Hegarty, G. F. Imbusch +1 more

Optics LettersNov 1, 197814 citations

STIMULATED EMISSION OF TUNABLE HIGH FREQUENCY PHONONS IN LaF3 : Er3+

D. J. Sox, John E. Rives, Richard S. Meltzer

We describe a case of stimulated emission of high frequency phonons (~ 0.2 THz) using optical excitation to invert the population of a pair of Kramer's states split in a magnetic field. The phonons are tunable with a magnetic field and the population inversion exists sufficiently long for phonon propagation over macroscopic sample dimensions. Analysis using rate equations suggests preferential emission along the axis of the optically excited volume.

Le Journal de Physique ColloquesDec 1, 19811 citation

Fluorescence and magnetic resonance spectra of Nd3+ and Er3+ ions in single crystals of LaCl3

CLYDE A. JUN. HUTCHISON, S. G. Utterback, Philip Meadows Martineau

Physical review. B, Condensed matterMar 1, 19894 citations

Mechanism of a population inversion between the4I11/2and4I13/2levels of the Er3+ion in Y3AI5O12crystals

V I Zhekov, Boris V. Zubov, Vladimir A. Lobachev +3 more

Soviet Journal of Quantum ElectronicsApr 30, 198020 citations

Fluorine spin frozen core in Pr^3+:LaF_3 observed by cross relaxation

Lawrence L. Wald, Matjaž Lukač, Erwin Louis Hahn

Journal of the Optical Society of America BMay 1, 199218 citations

Phonon-bottlenecked spin relaxation of Er$^{3+}$:CaWO$_4$ at milliKelvin temperatures

S. Rajendran, B. Mistri, P. K. Sharma +5 more

quant-pharXiv:2605.18208May 19, 20260 citations

Optics Letters

Spin-lattice relaxation by the direct process in optically excited Er^3+ in LaF_3

H. Wolfrum, K. Lanzinger, Karl Friedrich Renk

Published Jul 1, 1980• 10 citations

Publisher

Abstract

DOI: 10.1364/ol.5.000294

Related papers

Spin-lattice relaxation in the excited ^4S_3/2 state of Er^3+ in LaF_3

Matthijs M. Broer, John Hegarty, G. F. Imbusch +1 more

We have employed a purely optical method to measure spin-lattice relaxation in the lower excited (4)S(3/2) state of Er(3+) in LaF(3) at helium temperatures. Above 3 K the relaxation is dominated by an Orbach process through the upper (4)S(3/2) state. Below 3 K the relaxation is caused by some residual mechanism that obscures the Kramers-Van Vleck direct process. By relating the Orbach relaxation measurements to the homogeneous broadening of the upper (4)S(3/2) level, we determine values of the transition rates between the upper and lower (4)S(3/2) states.We have employed a purely optical method to measure spin-lattice relaxation in the lower excited (4)S(3/2) state of Er(3+) in LaF(3) at helium temperatures. Above 3 K the relaxation is dominated by an Orbach process through the upper (4)S(3/2) state. Below 3 K the relaxation is caused by some residual mechanism that obscures the Kramers-Van Vleck direct process. By relating the Orbach relaxation measurements to the homogeneous broadening of the upper (4)S(3/2) level, we determine values of the transition rates between the upper and lower (4)S(3/2) states.

Optics LettersNov 1, 197814 citations

STIMULATED EMISSION OF TUNABLE HIGH FREQUENCY PHONONS IN LaF3 : Er3+

D. J. Sox, John E. Rives, Richard S. Meltzer

Le Journal de Physique ColloquesDec 1, 19811 citation

Fluorescence and magnetic resonance spectra of Nd3+ and Er3+ ions in single crystals of LaCl3

CLYDE A. JUN. HUTCHISON, S. G. Utterback, Philip Meadows Martineau

This article presents the results of experiments in which the 19 429.67-${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ emission of an ${\mathrm{Ar}}^{+}$ laser is used to pump the ${Z}_{1}$ , $^{4}\mathrm{I}_{9/2}$ , \ensuremath{\mu}=(5/2\ensuremath{\rightarrow} ${F}_{1}$ , $^{2}\mathrm{G}_{9/2}$ , \ensuremath{\mu}=(1/2 transition of ${\mathrm{Nd}}^{3+}$ ions dilutely substituted at ${\mathrm{La}}^{3+}$ sites in ${\mathrm{LaCl}}_{3}$ crystals in an \ensuremath{\sim}1.6-K bath of liquid He. In some of the work ${\mathrm{Er}}^{3+}$ ions are also present. When an external magnetic field is applied electron paramagnetic resonance (EPR) absorption of microwave energy by either ${\mathrm{Nd}}^{3+}$ or ${\mathrm{Er}}^{3+}$ results in marked intensity changes of ${\mathrm{Nd}}^{3+}$ fluorescence emissions. The essential new feature of this work is the observation of the importance of the effects of the heating of the crystal above the bath temperature by both optical and microwave absorption. The heating by phonons generated in the radiationless transitions associated with the optical pumping cycle results in the emission of 17 E and D ${\mathrm{Nd}}^{3+}$ fluorescences not observed in previous work with the crystal at \ensuremath{\sim}1.6 K. Because of the encapsulation of the crystals in silica envelopes in these experiments, the heating effects are especially marked at higher laser powers.These new fluorescences result from the state population redistributions effected by the rise in temperature of the crystal. EPR microwave absorption by either ${\mathrm{Nd}}^{3+}$ or ${\mathrm{Er}}^{3+}$ accompanied by spin-lattice relaxation results in a further increase in crystal temperature and further ${\mathrm{Nd}}^{3+}$ state population redistributions with concommitant changes in the intensities of the fluorescence emissions from these states of ${\mathrm{Nd}}^{3+}$ . This affords a new mechanism for optically detected magnetic resonance (ODMR) of these rare-earth ions. This new mechanism for ODMR produces optical signals strikingly different from those previously studied which result from the changes in the populations of the two components of the ground ${Z}_{1}$ doublet of ${\mathrm{Nd}}^{3+}$ produced by ${Z}_{1}$ microwave absorption or by microwave absorption by the ${\mathrm{Er}}^{3+}$ ground doublet with subsequent transfer of Zeeman quanta between ${\mathrm{Er}}^{3+}$ and ${\mathrm{Nd}}^{3+}$ and resultant changes in optical pumping rates and fluorescence emissions. The factors contributing to the new mechanism for ODMR also account for the observed changes with temperature in the characters of the decays of the ODMR signals when microwave irradiation is terminated. With constant intensity laser irradiation in the absence of external magnetic fields the 28 observed fluorescence emissions oscillate in synchrony at frequencies (1/2 to (1/3 Hz, when the laser irradiation intensity lies in a certain narrow range. Several mechanisms considered as explanations of this phenomenon have failed to account for its observed features. It is clear, however, that these oscillations of emission intensity are accompanied by oscillations in the temperature of the crystal and of the populations of the emitting states.This article presents the results of experiments in which the 19 429.67-${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ emission of an ${\mathrm{Ar}}^{+}$ laser is used to pump the ${Z}_{1}$, $^{4}\mathrm{I}_{9/2}$, \ensuremath{\mu}=(5/2\ensuremath{\rightarrow}${F}_{1}$, $^{2}\mathrm{G}_{9/2}$, \ensuremath{\mu}=(1/2 transition of ${\mathrm{Nd}}^{3+}$ ions dilutely substituted at ${\mathrm{La}}^{3+}$ sites in ${\mathrm{LaCl}}_{3}$ crystals in an \ensuremath{\sim}1.6-K bath of liquid He. In some of the work ${\mathrm{Er}}^{3+}$ ions are also present. When an external magnetic field is applied electron paramagnetic resonance (EPR) absorption of microwave energy by either ${\mathrm{Nd}}^{3+}$ or ${\mathrm{Er}}^{3+}$ results in marked intensity changes of ${\mathrm{Nd}}^{3+}$ fluorescence emissions. The essential new feature of this work is the observation of the importance of the effects of the heating of the crystal above the bath temperature by both optical and microwave absorption. The heating by phonons generated in the radiationless transitions associated with the optical pumping cycle results in the emission of 17 E and D ${\mathrm{Nd}}^{3+}$ fluorescences not observed in previous work with the crystal at \ensuremath{\sim}1.6 K. Because of the encapsulation of the crystals in silica envelopes in these experiments, the heating effects are especially marked at higher laser powers.These new fluorescences result from the state population redistributions effected by the rise in temperature of the crystal. EPR microwave absorption by either ${\mathrm{Nd}}^{3+}$ or ${\mathrm{Er}}^{3+}$ accompanied by spin-lattice relaxation results in a further increase in crystal temperature and further ${\mathrm{Nd}}^{3+}$ state population redistributions with concommitant changes in the intensities of the fluorescence emissions from these states of ${\mathrm{Nd}}^{3+}$. This affords a new mechanism for optically detected magnetic resonance (ODMR) of these rare-earth ions. This new mechanism for ODMR produces optical signals strikingly different from those previously studied which result from the changes in the populations of the two components of the ground ${Z}_{1}$ doublet of ${\mathrm{Nd}}^{3+}$ produced by ${Z}_{1}$ microwave absorption or by microwave absorption by the ${\mathrm{Er}}^{3+}$ ground doublet with subsequent transfer of Zeeman quanta between ${\mathrm{Er}}^{3+}$ and ${\mathrm{Nd}}^{3+}$ and resultant changes in optical pumping rates and fluorescence emissions. The factors contributing to the new mechanism for ODMR also account for the observed changes with temperature in the characters of the decays of the ODMR signals when microwave irradiation is terminated. With constant intensity laser irradiation in the absence of external magnetic fields the 28 observed fluorescence emissions oscillate in synchrony at frequencies (1/2 to (1/3 Hz, when the laser irradiation intensity lies in a certain narrow range. Several mechanisms considered as explanations of this phenomenon have failed to account for its observed features. It is clear, however, that these oscillations of emission intensity are accompanied by oscillations in the temperature of the crystal and of the populations of the emitting states.

Physical review. B, Condensed matterMar 1, 19894 citations

Mechanism of a population inversion between the4I11/2and4I13/2levels of the Er3+ion in Y3AI5O12crystals

V I Zhekov, Boris V. Zubov, Vladimir A. Lobachev +3 more

Studies of the spectra of stimulated emission from Y 3 AI 5 O 12 :Er 3+ crystals ( 4 I 11/2 – 4 I 13/2 ) containing 20 wt. % activator ions, showed that, as the temperature decreased from 300 to 77°K, a change was observed in the emission wavelength (at T = 300°K it was found that λ 1 = 2.9364 μ λ 2 = 2.8310 μ and at T = 77°K it was found that λ 1 = 2.6930 μ , λ 2 = 2.8970 μ ). This could not be attributed to a thermal redistribution of the populations of the Stark components of the 4 I 11/2 and 4 I 13/2 upper and lower active levels. An analysis of the results showed that the temperature shift of the stimulated emission spectrum was due to changes in the processes of relaxation of excitation from the upper levels of the Er 3+ ion which caused substantial changes in the populations of the 4 I 11/2 and 4 I 13/2 multiplets.Studies of the spectra of stimulated emission from Y 3 AI 5 O 12 :Er 3+ crystals ( 4 I 11/2 – 4 I 13/2 ) containing 20 wt. % activator ions, showed that, as the temperature decreased from 300 to 77°K, a change was observed in the emission wavelength (at T = 300°K it was found that λ 1 = 2.9364 μ λ 2 = 2.8310 μ and at T = 77°K it was found that λ 1 = 2.6930 μ , λ 2 = 2.8970 μ ). This could not be attributed to a thermal redistribution of the populations of the Stark components of the 4 I 11/2 and 4 I 13/2 upper and lower active levels. An analysis of the results showed that the temperature shift of the stimulated emission spectrum was due to changes in the processes of relaxation of excitation from the upper levels of the Er 3+ ion which caused substantial changes in the populations of the 4 I 11/2 and 4 I 13/2 multiplets.

Soviet Journal of Quantum ElectronicsApr 30, 198020 citations

Fluorine spin frozen core in Pr^3+:LaF_3 observed by cross relaxation

Lawrence L. Wald, Matjaž Lukač, Erwin Louis Hahn

We report direct evidence for the presence of a spin-diffusion barrier, or frozen core, in Pr3+:LaF3. The evidence is obtained by examining the cross relaxation between the Pr and F nuclei in a magnetic field chosen so that a pair of the optical ground-state Pr3+ hyperfine energy levels matches the F splitting or a multiple of the F splitting. This level-crossing condition permits resonant flip–flop interactions with the nearest-neighbor frozen-core F spins to repopulate Pr3+ hyperfine levels emptied by laser hole burning and is detected as enhanced absorption of the laser beam. The coupling of core F spins to bulk F spins during Pr–F cross relaxation is measured by NMR of the bulk F spin magnetization. The rate of cross relaxation between the Pr spins and the bulk F spins measured in this way is at least 3–4 orders of magnitude slower than that expected in the absence of a spin-diffusion barrier. This reduction of coupling indicates nearly complete detuning of the frozen-core F spins immediately surrounding the Pr3+ ion, cutting off resonant coupling with the bulk F spins.We report direct evidence for the presence of a spin-diffusion barrier, or frozen core, in Pr3+:LaF3. The evidence is obtained by examining the cross relaxation between the Pr and F nuclei in a magnetic field chosen so that a pair of the optical ground-state Pr3+ hyperfine energy levels matches the F splitting or a multiple of the F splitting. This level-crossing condition permits resonant flip–flop interactions with the nearest-neighbor frozen-core F spins to repopulate Pr3+ hyperfine levels emptied by laser hole burning and is detected as enhanced absorption of the laser beam. The coupling of core F spins to bulk F spins during Pr–F cross relaxation is measured by NMR of the bulk F spin magnetization. The rate of cross relaxation between the Pr spins and the bulk F spins measured in this way is at least 3–4 orders of magnitude slower than that expected in the absence of a spin-diffusion barrier. This reduction of coupling indicates nearly complete detuning of the frozen-core F spins immediately surrounding the Pr3+ ion, cutting off resonant coupling with the bulk F spins.

Journal of the Optical Society of America BMay 1, 199218 citations

Phonon-bottlenecked spin relaxation of Er $^{3+}$ :CaWO $_4$ at milliKelvin temperaturesPhonon-bottlenecked spin relaxation of Er$^{3+}$:CaWO$_4$ at milliKelvin temperatures

S. Rajendran, B. Mistri, P. K. Sharma +5 more

We study spin-lattice relaxation times of electron spins in Er $^{3+}$ :CaWO $_4$ at millikelvin temperature, detected via their coupling to a low-mode volume superconducting resonator. At large magnetic field supporting strong phonon-emission rates, we observe a noticeable increase in relaxation times with increasing spin-excitations, which exhibit a unique $[\tanh (\hbar ω_0/k_\text{B} T)]^2$ temperature dependence. These observations are typical of a phonon-bottlenecked spin relaxation, and have implications for quantum technologies that exploit rare-earth spin ensembles as coherent resources.We study spin-lattice relaxation times of electron spins in Er$^{3+}$:CaWO$_4$ at millikelvin temperature, detected via their coupling to a low-mode volume superconducting resonator. At large magnetic field supporting strong phonon-emission rates, we observe a noticeable increase in relaxation times with increasing spin-excitations, which exhibit a unique $[\tanh (\hbar ω_0/k_\text{B} T)]^2$ temperature dependence. These observations are typical of a phonon-bottlenecked spin relaxation, and have implications for quantum technologies that exploit rare-earth spin ensembles as coherent resources.

quant-pharXiv:2605.18208May 19, 20260 citations

This article presents the results of experiments in which the 19 429.67-${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ emission of an

{\mathrm{Ar}}^{+}

laser is used to pump the

{Z}_{1}

^{4}\mathrm{I}_{9/2}

, \ensuremath{\mu}=(5/2\ensuremath{\rightarrow}

{F}_{1}

^{2}\mathrm{G}_{9/2}

, \ensuremath{\mu}=(1/2 transition of

{\mathrm{Nd}}^{3+}

ions dilutely substituted at

{\mathrm{La}}^{3+}

sites in

{\mathrm{LaCl}}_{3}

crystals in an \ensuremath{\sim}1.6-K bath of liquid He. In some of the work

{\mathrm{Er}}^{3+}

ions are also present. When an external magnetic field is applied electron paramagnetic resonance (EPR) absorption of microwave energy by either

{\mathrm{Nd}}^{3+}

{\mathrm{Er}}^{3+}

results in marked intensity changes of

{\mathrm{Nd}}^{3+}

fluorescence emissions. The essential new feature of this work is the observation of the importance of the effects of the heating of the crystal above the bath temperature by both optical and microwave absorption. The heating by phonons generated in the radiationless transitions associated with the optical pumping cycle results in the emission of 17 E and D

{\mathrm{Nd}}^{3+}

fluorescences not observed in previous work with the crystal at \ensuremath{\sim}1.6 K. Because of the encapsulation of the crystals in silica envelopes in these experiments, the heating effects are especially marked at higher laser powers.These new fluorescences result from the state population redistributions effected by the rise in temperature of the crystal. EPR microwave absorption by either

{\mathrm{Nd}}^{3+}

{\mathrm{Er}}^{3+}

accompanied by spin-lattice relaxation results in a further increase in crystal temperature and further

{\mathrm{Nd}}^{3+}

state population redistributions with concommitant changes in the intensities of the fluorescence emissions from these states of

{\mathrm{Nd}}^{3+}

. This affords a new mechanism for optically detected magnetic resonance (ODMR) of these rare-earth ions. This new mechanism for ODMR produces optical signals strikingly different from those previously studied which result from the changes in the populations of the two components of the ground

{Z}_{1}

doublet of

{\mathrm{Nd}}^{3+}

produced by

{Z}_{1}

microwave absorption or by microwave absorption by the

{\mathrm{Er}}^{3+}

ground doublet with subsequent transfer of Zeeman quanta between

{\mathrm{Er}}^{3+}

and

{\mathrm{Nd}}^{3+}

and resultant changes in optical pumping rates and fluorescence emissions. The factors contributing to the new mechanism for ODMR also account for the observed changes with temperature in the characters of the decays of the ODMR signals when microwave irradiation is terminated. With constant intensity laser irradiation in the absence of external magnetic fields the 28 observed fluorescence emissions oscillate in synchrony at frequencies (1/2 to (1/3 Hz, when the laser irradiation intensity lies in a certain narrow range. Several mechanisms considered as explanations of this phenomenon have failed to account for its observed features. It is clear, however, that these oscillations of emission intensity are accompanied by oscillations in the temperature of the crystal and of the populations of the emitting states.

Phonon-bottlenecked spin relaxation of Er

^{3+}

:CaWO

_4

at milliKelvin temperatures

We study spin-lattice relaxation times of electron spins in Er

^{3+}

:CaWO

_4

at millikelvin temperature, detected via their coupling to a low-mode volume superconducting resonator. At large magnetic field supporting strong phonon-emission rates, we observe a noticeable increase in relaxation times with increasing spin-excitations, which exhibit a unique

[\tanh (\hbar ω_0/k_\text{B} T)]^2

temperature dependence. These observations are typical of a phonon-bottlenecked spin relaxation, and have implications for quantum technologies that exploit rare-earth spin ensembles as coherent resources.