共查询到20条相似文献,搜索用时 15 毫秒
1.
The modulated oscillations within the photon echo pulse in the nondegenerate three-level system with two close-lying levels are investigated. The frequency of the modulated oscillations is related to the energy difference between the close-lying levels. It allows to identify levels situated within Doppler width of the spectral line. 相似文献
2.
Photon-echo-based devices have been proposed for many applications in data storage, image processing, and optical communications. Many of these applications would benefit if the output from the photon-echo process could be used as input in a second photon-echo process. We demonstrate the generation of such secondary echoes, using the amplified output from an initial photon-echo process. The amplification is performed with a Pr:ZBLAN fiber amplifier, which gives a gain of more than 300 at 606 nm when pumped with 320 mW of power at 476 nm. 相似文献
3.
Two closely spaced 778 nm, 4-ps pulses, two-photon resonant with the 5S-5D transition in Rb vapor generate a ground state grating, which later is excited by a similar third pulse, producing conical yoked superfluorescence echo on the 5S-6P, 420-nm transition. The intensity of this emission as a function of the relative delay between the leading excitation pulses is governed by the dynamics of Doppler dephasing and rephasing. This is the first observation of an echo effect induced by a spontaneous relaxation process. 相似文献
4.
Stimulated photon echoes (SPEs) with time duration comparable to the coherent lifetime and Rabi period have been investigated theoretically and experimentally with an angled beam configuration. The Rabi oscillation effects on both the transmitted field (optical nutation) and the SPE fields are explained by analytic solutions of Maxwell-Bloch equations. The theory also predicts that an echo can exist in the noncausal direction, and this was confirmed by experiments with Tm:YAG crystal. 相似文献
5.
The paper is devoted to a consideration of the motion of a three-level atom in two resonant light waves. A kinetic equation of the Fokker-Planck type for the atomic distribution function is derived, which is valid when the recoil energy is small compared to the linewidths of the resonant transitions. The detailed behaviour of the radiation force and the diffusion tensor are studied numerically. The case of exact resonance and the nonresonant case are both considered. It is shown that a detuning from exact resonance results in a drastic decrease of the resonant light pressure force. For the detuning we determine the condition, under which an efficient action of the light pressure on a three-level atom takes place. 相似文献
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We discuss the possibility of observing photon echoes in the infrared range from a surface monolayer. Three different detection schemes are considered: direct infrared detection, external up-conversion, and in-situ up-conversion. The external up-conversion scheme appears most promising, while the in-situ up-conversion scheme has the advantage of being highly surface specific. Dephasing relaxations of surface vibrational excitations should be measurable. 相似文献
8.
Using Stark-pulse-modulated photon echoes, we observe a novel type of rephasing phenomenon in a Eu(3+) - and Pr(3+) -codoped Y(2)SiO(5) crystal. By adjusting the Stark pulse during the rephasing and dephasing periods one can observe a full recovery of the photon echo, corresponding to perfect dephasing-rephasing balancing of the perturbations. We propose to use this effect as a spectroscopic technique to distinguish between reversible and irreversible Stark interactions. 相似文献
9.
P.R. Berman 《Optics Communications》1984,52(3):225-230
A theory is presented which describes the formation of photon echoes in an atomic vapor when a cw laser field (the “dressing” field) drives an atomic transition while a sequence of pulses is applied to a coupled transition. It is found that, with a two-pulse excitation scheme, as many as nine echoes may be produced. The relationship of these “dressed-atom” echoes to conventional photon echoes is discussed. 相似文献
10.
A photon echo experiment in Tm(3+):YAG is reported that shows, for the first time to the authors' knowledge, the time-domain equivalent of the transition from near- to far-field diffraction, including Talbot self-imaging effects. The experiment demonstrates the huge dispersion capability of photon echoes and opens the way to further exploration of space-time duality. 相似文献
11.
Highly efficient two-pulse and stimulated photon echoes are experimentally demonstrated in an absorbing medium. Recall efficiencies of 235% and 150% with excellent signal contrast are measured for two-pulse and stimulated photon echoes, respectively, in a Tm:YAG crystal with an absorption length of 3.8. The reported efficiencies do not include any correction for decay or beam profile. We believe that this is the first demonstration of an uncorrected echo efficiency greater than 100% with good signal fidelity in an optically thick medium. 相似文献
12.
We propose to use photon echoes in rare-earth-doped crystals to implement the Fourier-transform chirp algorithm. The process is considered for application to spectral analysis of fast radio-frequency signals. Compared with surface acoustic wave devices, the proposed scheme gives access to the larger bandwidths of rare-earth-doped crystals and greater flexibility. An experimental demonstration of the proposed process is reported. 相似文献
13.
I. I. Popov N. S. Vashurin S. E. Putilin A. U. Bahodurov 《Bulletin of the Russian Academy of Sciences: Physics》2017,81(5):551-553
A textured three-layer ZnO/Si(P)/Si(B) film in an uniform longitudinal magnetic field with a stregth of 0.4 T exhibits the effect of the polarization plane’s rotation from a stimulated photon echo signal formed at room temperature on the exciton states. At time interval τ12 set to zero and time interval τ23 = 720 and 900 fs, the angles of rotation are 27° and 19°, respectively. 相似文献
14.
We predict and observe a new class of echoes of atomic sublevel coherences induced by two impact excitations with resonant light pulses which may be either coherent or incoherent. The Zeeman-sublevel echoes in 3 2S of sodium were observed by using polarization selective detection technique under the excitation condition that the optical T2 (5 × 10-11 s) was much shorter than the pulse width (5 ns). Theoretical analysis also predicts the echoes involving coherence transfer between ground and excited states. 相似文献
15.
Microcavities constructed from materials with a second-order nonlinear coefficient have enabled efficient second-harmonic(SH) generation at a low power level. However, it is still technically challenging to realize double resonance with large nonlinear modal overlap in a microcavity. Here, we propose a design for a robust, tunable, and easy coupling double-resonance SH generation based on the combination of a newly developed fiber-based Fabry–Perot microcavity and a sandwich structure, whose num... 相似文献
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Femtosecond photon echoes from band-to-band transitions in GaAs 总被引:1,自引:0,他引:1
Becker PC Fragnito HL Brito Cruz CH Fork RL Cunningham JE Henry JE Shank CV 《Physical review letters》1988,61(14):1647-1649
18.
The spectral line shifts Δ(κ) due to the mixing collisions by means of the quantum beats of the photon echoes are analysed. 相似文献
19.
Laser cooling below a photon recoil with three-level atoms 总被引:1,自引:0,他引:1
20.
A bandpass filter based on guided-mode resonance effects in a single-layer periodic waveguide is presented. Strong refractive-index modulation is used to support the excitation of a resonance pair in which leaky waveguide mode TE0 is excited by the second diffraction order and TE2 by the first diffraction order. It is shown that one resonance provides a broad low-transmission band, whereas the other supplies the transmission peak through its asymmetrical line shape. A bandpass filter with central wavelength at 1.55 microm is presented to demonstrate this concept. 相似文献