The dependence of evanescent wave polarization on the losses of guided optical modes
arXiv:2102.06680 · doi:10.1103/PhysRevB.104.085417
Abstract
Spin-momentum locking of evanescent waves describes the relationship between the propagation constant of an evanescent mode and the polarization of its electromagnetic field, giving rise to applications in light nano-routing and polarimetry among many others. The use of complex numbers in physics is a powerful representation in areas such as quantum mechanics or electromagnetism; it is well known that a lossy waveguide can be modelled with the addition of an imaginary part to the propagation constant. Here we explore how these losses are entangled with the polarization of the associated evanescent tails for the waveguide, revealing a well-defined mapping between waveguide losses and the Poincaré sphere of polarizations, in what could be understood as a "polarization-loss locking" of evanescent waves. We analyse the implications for near-field directional coupling of sources to waveguides, as optimized dipoles must take into account the losses for a perfectly unidirectional excitation. We also reveal the potential advantage of calculating the angular spectrum of a source defined in a complex, rather than the traditionally purely real, transverse wavevector space formalism.
arXiv comment8 pages, 4 figures
References in corpus (21)
- Spin-orbit interactions of light
- Transverse and longitudinal angular momenta of light
- Quantum spin Hall effect of light
- Chiral nanophotonic waveguide interface based on spin-orbit coupling of light
- Universal spin-momentum locking of evanescent waves
- Strong coupling between single atoms and non-transversal photons
- Optical diode based on the chirality of guided photons
- Polarization engineering in photonic crystal waveguides for spin-photon entanglers
- Spin-orbit interaction of light induced by transverse spin angular momentum engineering
- Dynamic Consequences of Optical Spin-Orbit Interaction
- Universal Spin-Momentum Locked Optical Forces
- Plasmon scattering from single sub-wavelength holes
- Transverse spin and spin-orbit coupling in silicon waveguides
- Experimental demonstration of linear and spinning Janus dipoles for polarisation and wavelength selective near-field coupling
- The ubiquitous photonic wheel
- Far-field and near-field directionality in acoustic scattering
- Near-Field Directionality Beyond the Dipole Approximation: Electric Quadrupole and Higher-Order Multipole Angular Spectra
- Amplitude and phase control of guided modes excitation from a single dipole source:engineering far- and near-field directionality
- Optical forces from near-field directionalities in planar structures
- Evanescent Gravitational Waves
- Hybrid graphene/silicon integrated optical isolators with photonic spin-orbit interaction