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- Kröll, Stefan, et al.
(author)
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Influence of excited state Pr3+ on the relaxation of the Pr3+-YAlO3 3H4-1D2 transition
- 1991
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In: Physical Review B (Condensed Matter). - 0163-1829. ; 44:1, s. 30-34
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Journal article (peer-reviewed)abstract
- Two-pulse photon-echo measurements on the 0.1 at. % Pr3+:YAlO3 H-3(4)-D-1(2) transition suggest that the relaxation time depends on the density of excited states created by the excitation pulses. The dependence of the relaxation time on the intensity of each excitation pulse shows that our results are inconsistent with instantaneous spectral diffusion, a model often invoked in this type of experiment, where excited states created by the second pulse chiefly influence the relaxation time. A homogeneous linewidth contribution, noted in previous work as being of unknown origin, is eliminated at low excitation fluences.
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- Kröll, Stefan, et al.
(author)
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Intensity dependent photon echo relaxation in rare earth doped crystals
- 1990
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In: Physical Review B (Condensed Matter). - 0163-1829. ; 41:16, s. 11568-11571
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Journal article (peer-reviewed)abstract
- Photon-echo-relaxation measurements made on the 3H4-3P0 transition of 0.01 at. % Pr3+:YAG (where YAG represents yttrium aluminum garnet), 3H4-1D2 transition in 0.1 at. % Pr3+:YAlO3, and 7F0-5D0 transition in 0.25 at. % Eu3+:YAlO3 show that the photon-echo relaxation rate increases when the intensities of the excitation pulses are increased. Although a part of the relaxation-rate increase in Pr3+:YAG may be attributed to an instantaneous spectral diffusion (ISD) in which the presence of excited neighboring Pr3+ ions change the local field and the absorption frequency of the rare-earth ions, our data deviate significantly from the ISD-model predictions. An additional intensity-dependent relaxation mechanism is required to explain the results.
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- Xu, E. Y, et al.
(author)
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Nanosecond image processing using stimulated photon echoes
- 1990
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In: Optics Letters. - 0146-9592. ; 15:10, s. 562-564
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Journal article (peer-reviewed)abstract
- Processing of two-dimensional images on a nanosecond time scale is demonstrated using the stimulated photon echoes in a rare-earth-doped crystal (0.1 at. \% Pr3$+$:LaF3). Two spatially encoded laser pulses (pictures) resonant with the 3P0-3H4 transition of Pr3$+$ were stored by focusing the image pulses sequentially into the Pr3$+$:LaF3 crystal. The stored information is retrieved and processed by a third read pulse, generating the echo that is the spatial convolution or correlation of the input images. Application of this scheme to high-speed pattern recognition is discussed.
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