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

Le Journal de Physique Colloques

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

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

Published Dec 1, 1981• 1 citation
Publisher

Abstract

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.

DOI
10.1051/jphyscol:19816130

Related papers

Stimulated emission of 0.2-THz phonons in La F3 : Er3+

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

Stimulated emission of phonons in the 0.2-THz frequency range is observed in La${\mathrm{F}}_{3}$:${\mathrm{Er}}^{3+}$. The phonons are generated in the relaxation between the Kramers components of the $^{4}S_{\frac{3}{2}}(1)$ state of ${\mathrm{Er}}^{3+}$ split in a magnetic field after inverting the population with a pulsed tunable dye laser. The stimulated emission is identified from the temporal behavior of the luminescence from the upper Kramers component which shows a speedup in the relaxation during inversion. The population dynamics are analyzed with the rate equations for the system. Comparison with experiment indicates strong preferential stimulated emission along the axis of the cylindrically excited volume and a gain of up to 5 ${\mathrm{mm}}^{\ensuremath{-}1}$. The population inversion exists sufficiently long for phonon propagation over macroscopic distances and the phonon frequency is tunable with the magnetic field.

Physical review. B, Condensed matter•Apr 15, 1982•18 citations

Stimulated emission of phonons in an acoustical cavity

Peter A. Fokker, J. I. Dijkhuis, H. W. de Wijn

Stimulated emission is studied of phonons resonant with the metastable Zeeman-split E-bar${(}^{2}$E) doublet in ruby. Initial population inversion of this two-level system is prepared by selective pulsed optical pumping, and the ensuing stimulated emission of resonant phonons is observed via an accelerated growth of the luminescence intensity emanating from the lower level. Under favorable conditions, a periodic recurrence of the process of stimulated emission is observed, which points to a phonon cavity formed by the end faces of the crystal in combination with a limited interaction length of the resonant phonons. To analyze these phenomena in detail, use is made of rate equations for the phonon occupation and the level populations with explicit account of their position dependences. With plausible assumptions an analytic solution of these equations is achieved, which excellently fits the data. The effect of lattice anharmonicity is shown to depend on the phonon energy in agreement with the theoretical prediction.

Physical review. B, Condensed matter•Feb 1, 1997•45 citations

Suppression of stimulated phonon emission in ruby by a magnetic-field gradient

Peter A. Fokker, Richard S. Meltzer, Y. P. Wang +2 more

It is demonstrated that a magnetic-field gradient can suppress amplified stimulated emission of phonons taking place within the Zeeman-split E-bar${(}^{2}$E) doublet of ${\mathrm{Cr}}^{3+}$ in 700 ppm ruby. The doublet is initially inverted by selective pulsed optical pumping. The field gradient produces a gradient in the transition frequency, thereby reducing the gain of the amplifying medium. The experiments are described with rate equations in which the gain is accounted for by the interaction length over which the phonons remain at resonance.

Physical review. B, Condensed matter•Feb 1, 1997•12 citations

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

H. Wolfrum, K. Lanzinger, Karl Friedrich Renk

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.

Optics Letters•Jul 1, 1980•10 citations

Optically excited ruby as a saser: Experiment and theory

Lieuwe Gijsbert Tilstra, A. F. M. Arts, H. W. de Wijn

Avalanches of phonons are generated following population inversion of the Zeeman-split $\overline{E}(^{2}E)$ Kramers doublet in a single crystal of dilute ruby $({\mathrm{Al}}_{2}{\mathrm{O}}_{3}:{\mathrm{Cr}}^{3+})$ at $1.4\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The inversion is achieved in a narrow zone of limited extent by selective pulsed optical pumping, and the phonons are detected via luminescence. The associated acoustic wave emanating from the zone propagates through the crystal, reverberates in the acoustic cavity formed by the crystalline end faces, and engages in further amplification each time it passes through the zone until the inversion becomes exhausted. The systems thus acts as a saser (sound amplification by stimulated emission of radiation). The avalanche is adequately described by coherent Bloch equations governing the acoustic wave and the interacting spin polarization, the losses being due to surface scattering and divergence. This conclusion holds good upon reducing the resonance length of the zone by a gradient magnetic field. Finally, the frequency and angular distributions of the avalanche are measured by using two disjunct zones located at opposite ends of the crystal, one serving as generator and the other as detector, in conjunction with a gradient field and lateral displacement. The frequency spread is found to be compatible with the inhomogeneously broadened transition within $\overline{E}(^{2}E)$, while the angular divergence is determined by the geometry of the zone.

Physical Review B•Jul 9, 2007•19 citations

SASER action in optically excited ruby: Angular and spectral distribution

Lieuwe Gijsbert Tilstra, A. F. M. Arts, H. W. de Wijn

Selective pulsed optical excitation is used in 500-at.ppm ruby (Al 2 O 3 :Cr 3+ ) at 1.4 K to prepare complete population inversion of the Zeeman-split Ē( 2 E ) doublet in a zone of limited size. The inversion results in prolific stimulated emission of phonons resonant with the one-phonon transition connecting the doublet states. The phonons are detected via the R 1 luminescence. The angular and spectral distributions of the associated acoustic wave are measured using a geometry with inverted zones at either end of the crystal, one serving as generator and the other as detector. The divergence appears to be governed by the geometry of the zone, while the spectral distribution is, within errors, in keeping with the inhomogeneously broadened phonon transition.

Journal of Physics Conference Series•Dec 1, 2007•1 citation
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.
Stimulated emission of phonons in the 0.2-THz frequency range is observed in LaF3{\mathrm{F}}_{3}F3​:Er3+{\mathrm{Er}}^{3+}Er3+. The phonons are generated in the relaxation between the Kramers components of the 4S32(1)^{4}S_{\frac{3}{2}}(1)4S23​​(1) state of Er3+{\mathrm{Er}}^{3+}Er3+ split in a magnetic field after inverting the population with a pulsed tunable dye laser. The stimulated emission is identified from the temporal behavior of the luminescence from the upper Kramers component which shows a speedup in the relaxation during inversion. The population dynamics are analyzed with the rate equations for the system. Comparison with experiment indicates strong preferential stimulated emission along the axis of the cylindrically excited volume and a gain of up to 5 ${\mathrm{mm}}^{\ensuremath{-}1}$. The population inversion exists sufficiently long for phonon propagation over macroscopic distances and the phonon frequency is tunable with the magnetic field.
Stimulated emission is studied of phonons resonant with the metastable Zeeman-split E-bar(2{(}^{2}(2E) doublet in ruby. Initial population inversion of this two-level system is prepared by selective pulsed optical pumping, and the ensuing stimulated emission of resonant phonons is observed via an accelerated growth of the luminescence intensity emanating from the lower level. Under favorable conditions, a periodic recurrence of the process of stimulated emission is observed, which points to a phonon cavity formed by the end faces of the crystal in combination with a limited interaction length of the resonant phonons. To analyze these phenomena in detail, use is made of rate equations for the phonon occupation and the level populations with explicit account of their position dependences. With plausible assumptions an analytic solution of these equations is achieved, which excellently fits the data. The effect of lattice anharmonicity is shown to depend on the phonon energy in agreement with the theoretical prediction.
It is demonstrated that a magnetic-field gradient can suppress amplified stimulated emission of phonons taking place within the Zeeman-split E-bar(2{(}^{2}(2E) doublet of Cr3+{\mathrm{Cr}}^{3+}Cr3+ in 700 ppm ruby. The doublet is initially inverted by selective pulsed optical pumping. The field gradient produces a gradient in the transition frequency, thereby reducing the gain of the amplifying medium. The experiments are described with rate equations in which the gain is accounted for by the interaction length over which the phonons remain at resonance.
Avalanches of phonons are generated following population inversion of the Zeeman-split E‾(2E)\overline{E}(^{2}E)E(2E) Kramers doublet in a single crystal of dilute ruby (Al2O3:Cr3+)({\mathrm{Al}}_{2}{\mathrm{O}}_{3}:{\mathrm{Cr}}^{3+})(Al2​O3​:Cr3+) at 1.4K1.4\phantom{\rule{0.3em}{0ex}}\mathrm{K}1.4K. The inversion is achieved in a narrow zone of limited extent by selective pulsed optical pumping, and the phonons are detected via luminescence. The associated acoustic wave emanating from the zone propagates through the crystal, reverberates in the acoustic cavity formed by the crystalline end faces, and engages in further amplification each time it passes through the zone until the inversion becomes exhausted. The systems thus acts as a saser (sound amplification by stimulated emission of radiation). The avalanche is adequately described by coherent Bloch equations governing the acoustic wave and the interacting spin polarization, the losses being due to surface scattering and divergence. This conclusion holds good upon reducing the resonance length of the zone by a gradient magnetic field. Finally, the frequency and angular distributions of the avalanche are measured by using two disjunct zones located at opposite ends of the crystal, one serving as generator and the other as detector, in conjunction with a gradient field and lateral displacement. The frequency spread is found to be compatible with the inhomogeneously broadened transition within E‾(2E)\overline{E}(^{2}E)E(2E), while the angular divergence is determined by the geometry of the zone.
Selective pulsed optical excitation is used in 500-at.ppm ruby (Al 2 O 3 :Cr 3+ ) at 1.4 K to prepare complete population inversion of the Zeeman-split Ē( 2 E ) doublet in a zone of limited size. The inversion results in prolific stimulated emission of phonons resonant with the one-phonon transition connecting the doublet states. The phonons are detected via the R 1 luminescence. The angular and spectral distributions of the associated acoustic wave are measured using a geometry with inverted zones at either end of the crystal, one serving as generator and the other as detector. The divergence appears to be governed by the geometry of the zone, while the spectral distribution is, within errors, in keeping with the inhomogeneously broadened phonon transition.