Chiral modes and directional lasing at exceptional points

@article{Peng2016ChiralMA,
  title={Chiral modes and directional lasing at exceptional points},
  author={Bo Peng and Şahin Kaya {\"O}zdemir and Matthias Liertzer and Weijian Chen and Johannes Kramer and Huzeyfe Yılmaz and Jan Wiersig and Stefan Rotter and Lan Yang},
  journal={Proceedings of the National Academy of Sciences},
  year={2016},
  volume={113},
  pages={6845 - 6850}
}
Significance Exceptional points (EPs) emerge when a system with loss or gain is tuned such that its eigenvalues and the corresponding eigenstates coalesce. By operating close to two EPs, we achieved a dynamic control of the rotation direction of light in a whispering-gallery-mode (WGM) resonator. This enabled us to tune the emission direction of a WGM microlaser from bidirectional, when the system is away from the EPs, to unidirectional emission at EPs and to reverse the emission direction by… 
View on NAS
pnas.org
321 Citations
Highly Influential Citations
8
Background Citations
71
Methods Citations
12
Results Citations
2

Figures from this paper

321 Citations

Citation Type

Citation Type

Direct Generation of Tunable Orbital Angular Momentum Beams in Microring Lasers with Broadband Exceptional Points
Non-Hermitian exceptional points (EPs) represent a special type of degeneracy where not only the eigenvalues coalesce, but also the eigenstates tend to collapse on each other. Recent studies have…
Dynamical switching of lasing emission by exceptional point modulation in coupled microcavities
In a non-Hermitian optical system with loss and gain, an exceptional point (EP) will arise under specific parameters where the eigenvalues and eigenstates exhibit simultaneous coalescence. Here we…
Reconfigurable symmetry-broken laser in a symmetric microcavity
TLDR
A reconfigurable symmetry-broken microlaser in a symmetric ultrahigh-Q whispering gallery microcavity with the symmetric structure is demonstrated, in which a chirality of lasing field is empowered spontaneously by the optical nonlinear effect.
Exceptional Photon Blockade: Engineering Photon Blockade with Chiral Exceptional Points
Non-Hermitian spectral degeneracies, known as exceptional points (EPs), feature simultaneous coalescence of both eigenvalues and the associated eigenstates of a system. A host of intriguing EP effects…
Unidirectional lasing in nonlinear Taiji microring resonators
We develop a general formalism to study laser operation in active micro-ring resonators supporting two counterpropagating modes. Our formalism is based on the coupled-mode equations of motion for the…
Chiral and degenerate perfect absorption on exceptional surfaces
Engineering light-matter interactions using non-Hermiticity, particularly through spectral degeneracies known as exceptional points (EPs), is an emerging field with potential applications in areas…
Generalized Fano lineshapes reveal exceptional points in photonic molecules
TLDR
The interference detection scheme is extended by introducing generalized Fano lineshapes as a signature of the exceptional point occurrence in resonant-scattering experiments and hyperspectral mapping around an exceptional point in a coupled-cavity system is introduced.
A phonon laser operating at an exceptional point
Non-Hermitian physical systems have attracted considerable attention lately for their unconventional behaviour around exceptional points (EPs)—spectral singularities at which eigenvalues and…
Unidirectional light emission in PT-symmetric microring lasers.
TLDR
A unidirectional single-moded parity-time symmetric laser is shown by incorporating active S-bend structures with opposite chirality in the respective ring resonators by Measure the extinction ratio between the CW and CCW modes in a single ring resonator in the presence of an S- bend waveguide and experimentally investigate the uniddirectional emission in PT-symmetric systems below and above the exceptional point.
Successive switching among four states in a gain-loss-assisted optical microcavity hosting exceptional points up to order four
The implementation of exceptional points (EPs), a special type of topological singularities, has emerged as a new paradigm for engineering the quantum-inspired or wave-based photonic systems. Even…
...
...

References

SHOWING 1-10 OF 51 REFERENCES
Loss-induced suppression and revival of lasing
TLDR
Overturning conventional wisdom that loss is bad and should be minimized, Peng et al. show that carefully tweaking the coupling strength between the various components of a coupled optical system can actually result in an enhancement of the optical properties by adding more loss into the system.
Chiral nanophotonic waveguide interface based on spin-orbit interaction of light
TLDR
It is demonstrated that the directional flow of light in a fiber can be controlled by placing a single gold nanoparticle on or near the surface of the fiber by exploiting the chiral properties of light (the spin-orbit interaction) to create a chiral waveguide coupler.
Reversing the pump dependence of a laser at an exceptional point
TLDR
It is shown that exceptional points can be conveniently induced in a photonic molecule laser by a suitable variation of the applied pump, including a strongly decreasing intensity of the emitted laser light for increasing pump power.
Unidirectional emission from circular dielectric microresonators with a point scatterer
Circular microresonators are micron-sized dielectric disks embedded in material of lower refractive index. They possess modes of extremely high Q-factors (low-lasing thresholds), which makes them…
Structure of whispering-gallery modes in optical microdisks perturbed by nanoparticles
It is a well-known fact that a single nanoparticle placed in the evanescent field of an optical microdisk leads to coherent backscattering of light between counterpropagating whispering-gallery…
Controlled manipulation of mode splitting in an optical microcavity by two Rayleigh scatterers.
TLDR
Rich dynamics and tunability of split modes in a single microresonator will find immediate applications in optical sensing, opto-mechanics, filters and will provide a platform to study strong light-matter interactions in two-mode cavities.
Local chirality of optical resonances in ultrasmall resonators.
TLDR
The results demonstrate that the local chirality of optical resonances can be utilized to control the output directionality and enhance the collection efficiency of emission from ultrasmall resonators.
Non-Hermitian-transport effects in coupled-resonator optical waveguides
Coupled-resonator optical waveguides are known to have interesting and useful dispersion properties. Here, we study the transport in these waveguides in the general case where each resonator is open…
Parity–time synthetic photonic lattices
TLDR
The experimental observation of light transport in large-scale temporal lattices that are parity–time symmetric is reported and it is demonstrated that periodic structures respecting this symmetry can act as unidirectional invisible media when operated near their exceptional points.
Integrated Compact Optical Vortex Beam Emitters
TLDR
Silicon-integrated optical vortex emitters are demonstrated, using angular gratings to extract light confined in whispering gallery modes with high OAM into free-space beams with well-controlled amounts of OAM, confirming the theoretical prediction that the emitted beams carry exactly defined and adjustable OAM.
...
...