Optical vortex with a small core and Gaussian intensity envelope for light-matter interaction

Rumala, Yisa S.; Leanhardt, Aaron

doi:10.1364/josab.34.000909

Cited by 12 publications

(3 citation statements)

References 48 publications

(86 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As we can see that the Raman coupling �(r) and two-photon detuning δ serve as effective transverse and longitudinal Zeeman fields, respectively, which play crucial roles in stabilizing vortices. Different from the LG Raman beams used in previous experiments [53,55], Chen et al propose Raman coupling as �(r) = � 0 e −2r 2 /w 2 [66], with 0 the peak intensity and w the beam waist, which can be experimentally realized [120]. Such a choice of the Raman beams is mainly on the basis that the LG Raman beams used in current experiments are suppressed over a considerable region near r = 0 , giving rise to an almost vanishing spin mixing effect in the vicinity, which is unfavorable for vortex formation essentially.…”

Section: Soam-coupling-induced Vortex Statesmentioning

confidence: 99%

Spin-orbital-angular-momentum-coupled quantum gases

et al. 2022

View full text Add to dashboard Cite

We briefly review the recent progress of theories and experiments on spin-orbital-angular-momentum (SOAM)-coupled quantum gases. The coupling between the intrinsic degree of freedom of particles and their external orbital motions widely exists in the universe and leads to a broad variety of fundamental phenomena in both classical physics and quantum mechanics. The recent realization of synthetic SOAM coupling in cold atoms has attracted a great deal of attention and stimulated a large amount of considerations on exotic quantum phases in both Bose and Fermi gases. In this review, we present a basic idea of engineering SOAM coupling in neutral atoms, starting from a semiclassical description of atom-light interaction. Unique features of single-particle physics in the presence of SOAM coupling are discussed. The intriguing ground-state quantum phases of weakly interacting Bose gases are introduced, with emphasis on a so-called angular stripe phase, which has not yet been observed at present. It is demonstrated how to generate a stable giant vortex in a SOAM-coupled Fermi superfluid. We also discuss the topological characters of a Fermi superfluid in the presence of SOAM coupling. We then introduce the experimental achievement of SOAM coupling in $$^{87}$$ 87 Rb Bose gases and its first observation of phase transitions. The most recent development of SOAM-coupled Bose gases in experiments is also summarized. Regarding the controllability of ultracold quantum gases, it opens a new era, from the quantum simulation point of view, to study the fundamental physics resulting from SOAM coupling as well as newly emergent quantum phases.

show abstract

Section: Soam-coupling-induced Vortex Statesmentioning

confidence: 99%

Spin-orbital-angular-momentum-coupled quantum gases

et al. 2022

View full text Add to dashboard Cite

show abstract

“…S1, phase patterns e +ilθ and e −ilθ are imprinted by a q-plate respectively on the input pair of Gaussian beams with different circular polarizations. Subsequently, a 4f -lens system is employed to image the Gaussian intensity profile immediately after the q-late onto the atoms [32]. Unlike the situations in previous works [26,27], here we use the beam profile right after the q-plate and do not allow it to further propagate into the diffraction far field, thus avoiding the Laguerre function and the factor |r| l to appear in the intensity profile.…”

Section: Experimental Implementationmentioning

confidence: 99%

Generating Giant Vortex in a Fermi Superfluid via Spin-Orbital-Angular-Momentum Coupling

Chen

Peng

et al. 2020

Phys. Rev. Lett.

View full text Add to dashboard Cite

Spin-orbital-angular-momentum (SOAM) coupling has been realized in recent experiments of Bose-Einstein condensates [Chen et al., Phys. Rev. Lett. 121, 113204 (2018) and Zhang et al., Phys. Rev. Lett. 122, 110402 (2019)], where the orbital angular momentum imprinted upon bosons directly leads to quantized vortices. However, an s-wave Fermi pairing superfluid under the same SOAM coupling is typically vortex-less, as the two fermion species acquire opposite angular momenta in the center-of-mass motion. Here we show that, by introducing a moderate two-photon detuning in the Raman process generating the SOAM coupling, a quantized vortex, with size comparable to the beam waist of Raman lasers, can be stabilized in a Fermi superfluid. Such a giant vortex state can be viewed as the angular analogue of the Fulde-Ferrell states under a spin-orbit-coupling-induced Fermi-surface deformation, now with Cooper pairs carrying quantized angular momenta. Due to the spin-polarized nature of vortex bound states, these vortices feature a large spin polarization at the vortex core, thus providing an ideal signal for their experimental detection.

show abstract

“…Using smaller wavelength light will allow focusing that generates a much smaller beam waist, on the scale of λ. X-ray optical vortices have been studied and shown to produce circular-vortex-dichroic absorption signals in cysteine molecules with respect to the sign of ℓ that are larger than standard circular dichroism with circularly polarized photons [67]. Furthermore, optical vortices with large beam waists have been generated [68] which possess an intensity pattern with a Gaussian envelope and a point singularity at the centre, leading to vortex core size to beam waist ratios of w VC /w 0 ≈ 0.02. Another route, which has already been utilized to observe optical activity of twisted light [44], is the use of plasmonic enhancements of metallic nanoparticles to enhance the coupling between chiral molecules and optical vortex light [69].…”

Section: Optical Tensors Labelmentioning

confidence: 99%

Nonlinear chiral molecular photonics using twisted light: hyper-Rayleigh and hyper-Raman optical activity

Forbes

2020

J. Opt.

View full text Add to dashboard Cite

Chiroptical and optical activity effects involve differential interactions between matter and light. Generally this involves chiral molecules absorbing or scattering right- and left-handed circularly polarized photons at different rates due to the chiroptical interplay of molecular and optical chirality. Laser light which propagates with a helical phase and twisted wavefront possesses optical orbital angular momentum. These optical vortices can twist either clockwise or anticlockwise, and as such they exhibit an optical handedness or chirality completely distinct from that of circular polarization. It has recently been established that the linear optical effects of single-photon absorption and scattering can exhibit optical activity and chiroptical interactions with respect to the optical vortex handedness. Here a fundamental mechanism of optical activity for twisted light is exhibited in nonlinear processes, with specific emphasis on hyper-Rayleigh and hyper-Raman scattering. In comparison to unstructured or plane-wave light, it is shown that using twisted photons produces novel scattering mechanisms dependent on parameters unique to optical vortex beams. Specifically, the scattered intensity for both hyper-Rayleigh and hyper-Raman optical activity is dependent on the sign and magnitude of the OAM of the incident twisted photons, as well as the transverse position of the chiral scatterer. Moreover, symmetry analysis reveals that, unlike the recently discovered linear optical activity effects with optical vortices, nonlinear scattering of twisted light by chiral molecules leads to a modification of scattering through uniquely weighted individual hyperpolarizability contributions.

show abstract

Optical vortex with a small core and Gaussian intensity envelope for light-matter interaction

Cited by 12 publications

References 48 publications

Spin-orbital-angular-momentum-coupled quantum gases

Spin-orbital-angular-momentum-coupled quantum gases

Generating Giant Vortex in a Fermi Superfluid via Spin-Orbital-Angular-Momentum Coupling

Nonlinear chiral molecular photonics using twisted light: hyper-Rayleigh and hyper-Raman optical activity

Contact Info

Product

Resources

About