Dependence of two-photon absorption excited fluorescence in dye solutions on the angle between the linear polarizations of two intersecting beams

Experimental evidence is presented showing that when two linearly polarized beams intersect and cause two-photon absorption in a dye-doped solution, the strength of the resulting visible emission strongly depends on the angle between the beams polarizations. The two-photon absorption strength itself is shown to depend only on the electronic transition accessed, in agreement with previously reported studies. However, for three-dimensional display applications it is the visible emission strength that the viewer perceives that is of interest. Four different dyes in solution were used (coumarin 7 , rhodamine B, naphthofluorescein, and fluorescein) and several parameters that affect the polarization dependence of the visible signal strength were identified, including the excited state attained, the relative irradiance of each pump beam, and the solvent viscosity. PACS 33.80.Wz; 39.30.+w; 42.70.Jk     

One and two-photon absorption in multicomponent glasses and the measurement of cubic nonlinear susceptibility

One-and two-photon absorption of N₂-laser radiation (λ = 337 nm) in multicomponent silicate and phosphate glasses is investigated. A monotonic decrease from pulse to pulse in the intensity of radiation passing through a sample and in the luminescence excited by this radiation is found. The possibility of calculating the imaginary part of the cubic nonlinear susceptibility of glasses using the time dependence of the change in the laser intensity at the sample output is shown.     

双光子吸收材料用于高功率激光近场控制技术

 为了提高高功率激光光束质量和改善近场均匀性,在SILEX-Ⅰ超短脉冲激光装置的泵浦光系统上进行实验,研究了一种双光子吸收材料的光限幅特性及对激光近场的改善情况。利用泵浦光SAGA激光器输出的激光进行光限幅特性实验。结果表明:该材料具有明显的光功率限幅特性,且透过率较高,当入射光强小于0.60 GW/cm₂时,透过率大于90%。在SILEX-Ⅰ装置的泵浦光系统进行联机实验,研究了该材料对激光近场均匀性的改善。实验结果表明:经过材料后,激光近场均匀性和调制度有明显改善。     

双光子吸收材料用于高功率激光近场控制技术

为了提高高功率激光光束质量和改善近场均匀性,在SILEX-Ⅰ超短脉冲激光装置的泵浦光系统上进行实验,研究了一种双光子吸收材料的光限幅特性及对激光近场的改善情况。利用泵浦光SAGA激光器输出的激光进行光限幅特性实验。结果表明:该材料具有明显的光功率限幅特性,且透过率较高,当入射光强小于0.60 GW/cm2时,透过率大于90%。在SILEX-Ⅰ装置的泵浦光系统进行联机实验,研究了该材料对激光近场均匀性的改善。实验结果表明:经过材料后,激光近场均匀性和调制度有明显改善。     

Squeezing in two-photon absorption

The conditions for homodyne detection of squeezing are related to the density matrix of the squeezed light. It is shown that coherent light subjected to two-photon absorption for an appropriate length of time develops a small amount of squeezing.     

Plasmonic generation of sound by counterpropagating light beams in semiconductors

The possibility of generating longitudinal sound waves on a deformation potential in a semiconductor medium has been investigated. This generation is due to the excitation of internal longitudinal electric field in the plasma electron subsystem of semiconductor by external counterpropagating light beams.     

Analytic continuation of sturmian expansions for two-photon ionization

We show that the sturmian expansions of transition amplitudes for two-photon ionization may be handled as ordinary (single variable) power series, and we describe a simple method for performing their analytic continuation above the photoelectric threshold. Numerical results are presented for the hydrogenic states 1s, 2s, and 2p.