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Communication systems and network technologies
Published in Kennis Chan, Future Communication Technology and Engineering, 2015
[6] Allen L et al. 1992. Orbital angular momentum of light and the transformation of Laguerre-Gaussian laser modes. Physical Review A45(11):8185−8189. [7] Thidé B et al. 2007. Utilization of photon orbital angular momentum in the low-frequency radio domain. Physical review letters 99(8):087701.
Emerging Two-Dimensional Materials and Their Applications in Detection of Polarized Light
Published in Song Sun, Wei Tan, Su-Huai Wei, Emergent Micro- and Nanomaterials for Optical, Infrared, and Terahertz Applications, 2023
Xiao Luo, Qing Liu, Huidong Yin, Fucai Liu
In general, the CPGE results from the interaction between the material asymmetry and the spin angular momentum of light. Therefore, it can be regarded as a critical detecting way to analyze the change of information of electrons or holes in the microscopic level. Furthermore, we can obtain more information of light by CPGE, such as amplitude, phase, and polarization of light. The section is aimed to reveal the basic principles of CPGE detection in different material systems such as quantum wells, TMDCs, topological insulators, Weyl semimetals, among others.
Mass data methods
Published in W. Schofield, M. Breach, Engineering Surveying, 2007
Gyroscopes may sense rotation or rotation rate from the Coriolis effect, angular momentum or light path properties using measurements of angular displacement, torque rebalance, vibration, rotation, ring lasers or fibre optic lasers.
Fabrication of optical vortex array by fixing standing wave mediated periodic defects in nematic liquid crystals via photopolymerization
Published in Liquid Crystals, 2022
Vijay Kumar Baliyan, Doyeon Lee, Jiseon Yang, Vitaly P. Panov, Jang-Kun Song
Optical vortices, also known as orbital angular momentum (OAM) beams, have recently attracted significant attention owing to their remarkable and unique features and potential for application in several fields. In 1992, Allen et al. first showed that optical vortex beams comprising an azimuthal phase term, exp(ilφ), possess an OAM of lħ per photon, where l is the topological charge and φ is the azimuthal angle [1–3]. The OAM of optical vortices differs from the spin angular momentum of light, which is related to the polarisation of light. At the singularity, the phase cannot be determined, and the amplitude vanishes; consequently, a dark centre emerges within the wave packet. This topological structure is not limited to the wavefront of light; it can also be found in acoustic waves [4], electrons [5,6], and neutrons [7]. Optical vortex beams have been studied substantially in various fields and applications [2,3,8–10], such as optical manipulation, optical trapping, optical tweezers, optical vortex knots, microscopy, sensing, metrology, imaging, and quantum information processing [11–16].
Inexplicability of Beth’s experiment within the framework of Maxwell’s electrodynamics
Published in Journal of Modern Optics, 2021
The sense of the spin tensor (15) is as follows. The component is a volume density of spin. This means that is the spin of the electromagnetic field inside the spatial element . The component is the flux density of spin flowing in the direction of the axis. For example, is the z-component of spin passing through the surface element per unit time, i.e. the torque acting on the surface element. That is, is Poynting’s G, and spin density is proportional to energy density. The spin tensor is now successfully used to calculate the spin angular momentum of light [19–26]. However, there is no spin tensor in Maxwell’s electrodynamics. The role of the Belinfante–Rosenfeld procedure [27,28] in the annihilation of the spin tensor (15) is analysed in detail [29,30].
Orbital and spin parts of energy currents for electromagnetic waves through spatially inhomogeneous media
Published in Journal of Modern Optics, 2018
As another example, investigations are performed on the translation-invariant optical fibres (14), where the refractive index is varied over the transverse cross-sectional area. It is shown particularly in (14) how spatial material inhomogeneity leads to the spin–orbit interaction (SOI). Several techniques imparting angular momentum to light are also described in (14,25). Thermal lensing is yet another way of achieving index profiling. In the field of optical fibres, radially varying index profiles have been employed to generate beams with desired properties of angular momentum (28). Additional examples of material inhomogeneities can be found in (34,35).