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11.
Yong Ran Tianbo Zhang Jiayin Qin 《International Journal of Infrared and Millimeter Waves》1997,18(10):1917-1925
Based on the density matrix theory of quantum system, the spectra of optically pumped superradiant and cavity NH3 far-infrared (FIR) lasers were calculated by means of iteration method. The calculation showed that, compared with the optically
pumped superradiant FIR laser, the cavity laser had a wider band spectrum of FIR emission and a higher output power under
certain condition, moreover, the spectra of cavity laser had multi longitudinal-mode structure.
Supported by the Research Foundation of Hubei Province Education Committee, PRC 相似文献
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Guangyong Zhuo Xiaomei Wang Dong Wang Chun Wang Xian Zhao Zongshu Shao Minhua Jiang 《Optics & Laser Technology》2001,33(4)
A new organic dye trans-4-[p-(N-ethyl-N-hydroxyethylamino)styryl]-N-methylpyridinium iodide (abbreviated as HEASPI hereafter) with large two-photon absorption (TPA) cross section and excellent upconverted superradiance properties was synthesized in our group recently. The TPA cross section was measured to be σ2′=7.0×10−48 cm4 s/photon by using an open aperture Z-scan system. Linear absorption, single-photon induced fluorescence, two-photon induced fluorescence and two-photon pumped (TPP) upconverted superradiance properties were systematically studied. The highest net upconversion efficiency from the absorbed pump energy to the output upconverted superradiance energy is as high as 19.6% at the pump energy of 2.07 mJ from a mode-locked Nd : YAG picosecond laser. The dye solution also shows a clear optical power limiting effect. 相似文献
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We analytically study the superradiant instability of charged massless scalar field in the background of D-dimensional Reissner–Nordstr¨om(RN) black hole caused by mirror-like boundary condition. By using the asymptotic matching method to solve the Klein–Gordon equation that governs the dynamics of scalar field, we have derived the expressions of complex parts of boxed quasinormal frequencies, and shown they are positive in the regime of superradiance.This indicates the charged scalar field is unstable in D-dimensional Reissner–Nordstr¨om(RN) black hole surrounded by mirror. However, the numerical work to calculate the boxed quasinormal frequencies in this system is still required in the future. 相似文献
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Aranya B. Bhattacherjee 《理论物理通讯》2012,58(6):840-846
We investigate the effects of a movable mirror (cantilever) of an optical cavity on the superradiant light scattering from a Bose-Einstein condensate (BEC) in an optical lattice. We show that the mirror motion has a dynamic dispersive effect on the cavity-pump detuning. Varying the intensity of the pump beam, one can switch between the pure superradiant regime and the Bragg scattering regime. The mechanical frequency of the mirror strongly influences the time interval between two Bragg peaks. We find that when the system is in the resolved side band regime for mirror cooling, the superradiant scattering is enhanced due to coherent energy transfer from the mechanical mirror mode to the cavity field mode. 相似文献
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M. Block O. Rehm P. Seibert G. Werth 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,7(3):461-465
We have measured the lifetime of the metastable 3D
5/2
level in Ca+ using the “quantum jump" technique on a single stored and laser cooled ion in a linear Paul trap. We found a linear dependence
of the measured decay rate on the power of the laser which repumps the ions from the long lived 3D
3/2
level. This can be explained by off-resonant depletion of the 3D
5/2
level. The proper lifetime of this level is obtained by a linear extrapolation of the measured lifetime to zero laser power.
We obtain 1100(18) ms in agreement with theoretical calculations. The observed systematic change of the decay rate resolves
discrepancies between earlier experiments in which this effect had not been considered. Measurements on a linear chain of
10 laser cooled ions showed unexpected frequent coincidences of quantum jumps within our observation time of 20 ms. This indicates
a so far unexplained correlation between the ions in the chain at large distances.
Received 3 March 1999 相似文献
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We investigate the quantum dynamics of two defect centers in solids,which are coupled by vacuum-induced dipole-dipole interactions.When the interaction between defects and phonons is taken into account,the two coupled electron-phonon systems make up two equivalent multilevel atoms.By making Born-Markov and rotating wave approximations,we derive a master equation describing the dynamics of the coupled multilevel atoms.The results indicate the concepts of subradiant and superradiant states can be applied to these systems and the population transfer process presents different behaviors from those of the two dipolar-coupled two-level atoms due to the participation of phonons. 相似文献