Kochhenry3043

The photo-excited electrons and holes move in the same direction in the diffusion and in the opposite direction in the drift under an electric field. Therefore, the contribution to the inverse spin Hall current of photo-excited electrons and holes in the diffusion regime is different to that in the drift regime under electric field. By comparing the classical Hall effect with the inverse spin Hall effect in both diffusion and drift regime, we develop an optical method to distinguish the contributions of electrons and holes in the inverse spin Hall effect. It is found that the contribution of the inverse spin Hall effect of electrons and holes in an InGaAs/AlGaAs un-doped multiple quantum well is approximately equal at room temperature.Optical nanofiber is a widely adopted platform for highly efficient light-matter interaction by virtue of its exposed evanescent field with high light intensity. However, the strongly constrained mode field with the wavelength-scale size makes the light-matter interaction time limited in consideration of the random thermal motion of warm molecules, which results in considerable transit-time dephasing and thus line broadening. Here we report a systematic study of the transit-time effect associated with the optical nanofibers. Both simulation and experiment for nanofibers exposed in acetylene demonstrate the considerable transit-time broadened linewidth in the low-pressure range.We investigated beam shifts for an arbitrarily polarized vortex beam reflected and transmitted at two-dimensional (2D) anisotropic monolayer graphene surface. And generalized expressions are theoretically derived for calculating beam shifts of vortex beam. Then, we presented the beam shifts associated with the self-isotropic (SI) effect, self-anisotropic (SA) effect and cross-coupling (XC) effect originated from self-isotropic interaction, self-anisotropic interaction and cross-coupling interaction between isotropic and anisotropic of two-dimensional media, respectively. More importantly, novel optical phenomena resulting from the XC effect are flexibly shown by manipulation OAM. We believe that our results can be extensively extended to 2D anisotropic Dirac semimetals and Weyl semimetals, and expect the results to be significant and contribute to the understanding of the spin and orbit Hall effect of the light.To meet the requirement of high-accuracy pointing of quantum signals in satellite-to-ground quantum communication, this paper proposes a flexible satellite-based pointing method that changes the fine tracking point to solve the problem from point-ahead angle and ground beacon laser offset. This method does not require the use of a point-ahead mechanism and can detect the pointing angle in real time. Detailed algorithms and analysis are given. The method has been verified in orbit on the quantum science satellite Micius. The satellite-to-ground test results show that the quantum signal pointing accuracy is between 0.5∼1.0 µrad, which meets the efficiency requirements of satellite-to-ground quantum communication.We provide experimental evidence that stable vortex-solitons in nematic liquid crystals, termed vortex nematicons, can be generated in planar cells without any external biases, neither electric nor magnetic. We report on nonlinear vortices with extraordinary-wave beams in various undoped samples, pin-pointing how material nonlocality and birefringence aid their stable propagation. Finally, we also demonstrate confinement and waveguiding of an incoherent co-polarized probe signal by the nonlinear vortex.We theoretically show that optical vortices conserve the integer topological charge (TC) when passing through an arbitrary aperture or shifted from the optical axis of an arbitrary axisymmetric carrier beam. PF-04418948 in vitro If the beam contains a finite number of off-axis optical vortices with same-sign different TC, the resulting TC of the beam is shown to equal the sum of all constituent TCs. If the beam is composed of an on-axis superposition of Laguerre-Gauss modes (n, 0), the resulting TC equals that of the mode with the highest TC. If the highest positive and negative TCs of the constituent modes are equal in magnitude, the "winning" TC is the one with the larger absolute value of the weight coefficient. If the constituent modes have the same weight coefficients, the resulting TC equals zero. If the beam is composed of two on-axis different-amplitude Gaussian vortices with different TC, the resulting TC equals that of the constituent vortex with the larger absolute value of the weight coefficient amplitude, irrespective of the correlation between the individual TCs. In the case of equal weight coefficients of both optical vortices, TC of the entire beam equals the greatest TC by absolute value. We have given this effect the name "topological competition of optical vortices".High average power high-intensity laser systems can suffer from a heat-induced deformation of the final compressor gratings, which introduces wavefront aberrations and spatio-temporal couplings to the pulse. Here, we use a simple numerical description, that was first introduced by Li et al. (Appl. Phys. Express, 10, 102702, 2017 and Optics Express, 26, 8453, 2018), to calculate the resulting degradation of the peak intensity and the 3-dimensional deformation of the laser pulse as a function of average power, and verify the results using experimental data. For a typical 100 TW-class laser we find that non-negligible pulse distortions can occur at an average power as low as 2.7 Watts. An open source implementation of our numerical description is available for researchers to estimate the effects of spatio-temporal couplings for their specific laser configuration.We investigate the fundamental limitations of dispersion mitigation filters. By analyzing the dispersion compensating process from basic principles, we demonstrate how a digital filter can mitigate arbitrarily weak dispersion without oversampling. We calculate the maximum distance the signal can pass with and without dispersion compensation, beyond which no data decoding is possible. Furthermore, we show the exact mathematical relation between this maximum distance and the length of the compensating filter - with and without a Forward Error Correction (FEC).