Array Of Optical Cavities Research Articles

Remote Non-Invasive Fabry-Pérot Cavity Spectroscopy for Label-Free Sensing.

One way of optically monitoring molecule concentrations is to utilise the high sensitivity of the transmission and reflection rates of Fabry-Pérot cavities to changes of their optical properties. Up to now, intrinsic and extrinsic Fabry-Pérot cavity sensors have been considered with analytes either being placed inside the resonator or coupled to evanescent fields on the outside. Here we demonstrate that Fabry-Pérot cavities can also be used to monitor molecule concentrations non-invasively and remotely, since the reflection of light from the target molecules back into the Fabry-Pérot cavity adds upwards peaks to the minima of its overall reflection rate. Detecting the amplitude of these peaks reveals information about molecule concentrations. By using an array of optical cavities, a wide range of frequencies can be probed at once and a unique optical fingerprint can be obtained.

One-dimensional one-band topologically nontrivial non-Hermitian system simulated in optical cavities

We propose a scheme for simulating a momentum dependent non-Hermitian Hamiltonian term by adding loss in the hopping process in a one-dimensional array of optical cavities, which leads to a one-band topological nontrivial non-Hermitian model. We find that there is a kind of transition from all real energy spectrum to all imaginary one under open boundary conditions: the eigenvalues are all real or imaginary dependent on which amplitude of the Hermitian or non-Hermitian part is dominant even though the eigenvalues of the bulk system are complex under the periodic boundary condition. In addition, for such a non-Hermitian Hamiltonian, the left eigenvectors are the mirror symmetry of the right eigenvectors. Finally, by using the input-output formula, we show that the distribution of the boundary states can be directly observed by detecting the optical transmission in both cases.

Nonequilibrium photonic transport and phase transition in an array of optical cavities

We characterize photonic transport in a boundary driven array of nonlinear optical cavities. We find that the output field suddenly drops when the chain length is increased beyond a threshold. After this threshold a highly chaotic and unstable regime emerges, which marks the onset of a super-diffusive photonic transport. We show the scaling of the threshold with pump intensity and nonlinearity. Finally, we address the competition of disorder and nonlinearity presenting a diffusive-insulator phase transition.

Quantum simulation of 2D topological physics in a 1D array of optical cavities.

Orbital angular momentum of light is a fundamental optical degree of freedom characterized by unlimited number of available angular momentum states. Although this unique property has proved invaluable in diverse recent studies ranging from optical communication to quantum information, it has not been considered useful or even relevant for simulating nontrivial physics problems such as topological phenomena. Contrary to this misconception, we demonstrate the incredible value of orbital angular momentum of light for quantum simulation by showing theoretically how it allows to study a variety of important 2D topological physics in a 1D array of optical cavities. This application for orbital angular momentum of light not only reduces required physical resources but also increases feasible scale of simulation, and thus makes it possible to investigate important topics such as edge-state transport and topological phase transition in a small simulator ready for immediate experimental exploration.

Existence of Majorana fermion mode and Dirac equation in cavity quantum electrodynamics

We present the results of low lying collective mode of coupled optical cavity arrays. We derive the Dirac equation for this system and explain the existence of Majorana fermion mode in the system. We present quite a few analytical relations between the Rabi frequency oscillation and the atom–photon coupling strength to explain the different physical situation of our study and also the condition for massless collective mode in the system. We present several analytical relations between the Dirac spinor field, order and disorder operators for our systems. We also show that the Luttinger liquid physics is one of the intrinsic concepts in our system.

Two-component Bose-Hubbard model in an array of cavity polaritons

We propose a scheme which can realize an extended two-component Bose-Hubbard model using polaritons confined in an array of optical cavities. In addition to the density-dependent interactions, this model also contains nonlinear coupling terms between the two components of the polariton. Using a mean-field calculation, we obtain the phase diagram which shows how these terms affect the transition between the Mott insulator and the superfluid phase. In addition, we employ both a perturbation approach and an exact diagonalization method to gain more insights into the phase diagram.

Optical quantum simulation of Abelian gauge field using cold atomic ensembles coupled with arrays of optical cavities

A potentially practical scheme is proposed to realize optical quantum simulation of artificial Abelian gauge field in a scalable architecture consisting of cold atomic ensembles with optical cavities. In the present model, the collective excitations of cold atomic ensembles can be converted to the bosonic modes within the low-excitation limit, where the structure of two-dimension (2D) square plaquette enables the polaritons to move like a charged particle subjected to an external magnetic field. We find that the energy spectrum of this hybrid system exhibits a shape of Hofstadter buttery. Our work provides a different perspective to the quantum simulation of condensed matter and many-body physics in the context of cavity quantum electrodynamics. The experimental feasibility are justified using the existing techniques.

Quantum criticality of geometric phase in coupled optical cavity arrays under linear quench

The atoms trapped in microcavities and interacting through the exchange of virtual photons can be modeled as an anisotropic Heisenberg spin-1/2 lattice. We study the dynamics of the geometric phase of this system under the linear quenching process of laser field detuning, which shows XX criticality of the geometric phase and also gives the result of quantum criticality for different quenching rates.

Quantum phase transition of light in coupled optical cavity arrays: A renormalization group study

We study the quantum phase transition of light of a system when atom trapped in microcavities and interacting through the exchange of virtual photons. We predict the quantum phase transition between the photonic Coulomb blocked induce insulating phase and anisotropic exchange induced photonic superfluid phase in the system due to the existence of two Rabi frequency oscillations. The renormalization group equation shows explicitly that for this system there is no self-duality. The system also shows two Berezinskii-Kosterlitz-Thouless (BKT) transitions for the different physical situation of the system. The presence of single Rabi frequency oscillation in the system leads to the BKT transition where system shows the quantum phase transition from photonic metallic state to the Coulomb blocked induced insulating phase. For the other BKT transition when the z-component of exchange interaction is absent, the system shows the transition from the photonic metallic state to the photonic superfluid phase. We also predict the commensurate to incommensurate transition under the laser field detuning.

Elementary array of Fabry-Pérot waveguide resonators with tunable coupling

We recently proposed that an array of optical cavities containing quantum emitters could be interconnected by an optical bus made of Fabry Pérot resonators lying side by side, for applications in quantum information processing and quantum simulation. Here, we demonstrate the feasibility of this geometry. We show that the resonators can be conveniently coupled, and that the coupling rate between adjacent waveguides can be widely tuned using the thermo-optic effect. The device is linearly scalable and can be combined with other integrated devices, making it more generally applicable as an adjustable optical delay line or optical interconnect.

Design and analysis of photonic crystal coupled cavity arrays for quantum simulation

We performed an experimental study of coupled optical cavity arrays in a photonic crystal platform. We find that the coupling between the cavities is significantly larger than the fabrication-induced disorder in the cavity frequencies. Satisfying this condition is necessary for using such cavity arrays to generate strongly correlated photons, which has potential application in the quantum simulation of many-body systems.

Quantum field theoretical study of an effective spin model in coupled optical cavity arrays

Atoms trapped in micro-cavities and interacting through the exchange of virtual photons can be modeled as an anisotropic Heisenberg spin-1/2 lattice. We do the quantum field theoretical study of such a system using the Abelian bosonization method followed by the renormalization group analysis. An infinite order Berezinskii–Kosterliz–Thouless transition is replaced by second order XY transition even when an infinitesimal anisotropy in exchange coupling is introduced. We predict a quantum phase transition between the photonic Coulomb blocked induce Mott insulating and photonic superfluid phases due to detuning between the cavity and laser frequency. A large detuning favors the photonic superfluid phase. We also perform the analysis of Jaynes and Cumming Hamiltonian to support the results of quantum field theoretical study.

Discrete Snaking: Multiple Cavity Solitons in Saturable Media

A one-dimensional lattice equation is studied that models the light field in an optical system comprised of a periodic array of optical cavities pumped by a coherent light source. The model includes effects of linear detuning, linear and nonlinear dissipation, and saturable nonlinearity. A wide variety of different parameter regions are studied in which there is bistability between low-power and high-power spatially homogeneous steady states. By posing the steady problem as a time-reversible four-dimensional discrete map, it is shown that temporal stability of these states is a necessary condition for the existence of spatially localized modes. Numerical path-following is used to find both so-called bright solitons (whose core is at a higher intensity than the tails) and grey solitons (with nonzero lower intensity tails), whose temporal stability is also computed. Starting from the case of focusing nonlinearity in the continuum limit and with energy conservation, the effects of dissipation and spatial discreteness are studied both separately and in combination. The presence of Maxwell points, where heteroclinic connections exist between different homogeneous states, is found to lead to snaking bifurcation diagrams where the width of the soliton grows via a process of successive increase and decrease of a parameter representing the pump strength. These structures are found to cause parameter intervals where there are infinitely many distinct stable solitons, both bright and grey. Mechanisms are revealed by which the snakes can be created and destroyed as a second parameter is varied. In particular, the bright solitons reach the boundary of the bistability region where the homogeneous state in the soliton's tail undergoes a fold, whereupon the snake splits into many separate loops. More complex mechanisms underlie the morphogenesis of the grey soliton branches, for example, due to a fold of the homogeneous state that forms the core of the snaking soliton. Further snaking diagrams are found for both defocusing and purely dissipative nonlinearities, and yet further mechanisms are unraveled by which the snakes are created or destroyed as the two parameters vary.