Secondary bifurcations of hexagonal patterns in a nonlinear optical system: Alkali metal vapor in a single-mirror arrangement

Gamila, D.; Colet, Pere; Ackemann, T.; Westhoff, E. Grosse; Lange, W.

doi:10.1103/physreve.69.036205

Cited by 9 publications

(3 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Coherent nonlinear optics, driven by laser-matter interactions, is among the areas where these modulational patterns have been fruitfully studied. The optical systems displaying these patterns include lasers, [5][6][7][8] Kerr media and optical parametric oscillators, [9][10][11] atomic gases, [12][13][14][15][16] photorefractive crystals, [17] liquid crystal light valves, [18,19] and, most recently, semiconductor quantum well microcavities [20][21][22][23][24][25]. In most cases, phase-conjugate wave-mixing processes drive directional instabilities in the wave field fed by a uni-directional input light beam.…”

Section: Introductionmentioning

confidence: 99%

A population-competition model for analyzing transverse optical patterns including optical control and structural anisotropy

et al. 2015

View full text Add to dashboard Cite

We present a detailed study of a low-dimensional population-competition (PC) model suitable for analysis of the dynamics of certain modulational instability patterns in extended systems. The model is applied to analyze the transverse optical exciton-polariton patterns in semiconductor quantum well microcavities. It is shown that, despite its simplicity, the PC model describes quite well the competitions among various two-spot and hexagonal patterns when four physical parameters, representing density saturation, hexagon stabilization, anisotropy, and switching beam intensity, are varied. The combined effects of the last three parameters are given detailed considerations here. Although the model is developed in the context of semiconductor polariton patterns, its equations have more general applicability, and the results obtained here may benefit the investigation of other pattern-forming systems. The simplicity of the PC model allows us to organize all steady state solutions in a parameter space 'phase diagram'. Each region in the phase diagram is characterized by the number and type of solutions. The main numerical task is to compute inter-region boundary surfaces, where some steady states either appear, disappear, or change their stability status. The singularity types of the boundary points, given by Catastrophe theory, are shown to provide a simple geometric overview of the boundary surfaces. With all stable and unstable steady states and the phase boundaries delimited and characterized, we have attained a comprehensive understanding of the structure of the four-parameter phase diagram. We analyze this rich structure in detail and show that it provides a transparent and organized interpretation of competitions among various patterns built on the hexagonal state space.Beyond the primary instability of the spatially uniform state, the interplay among these wave-mixing processes gives rise to a variety of competing modulational patterns which may be regarded as optical analogs of perhaps more familiar patterns in macroscopic chemical, biological, and fluid dynamics systems [26][27][28][29]. Besides being fascinating nonlinear optical phenomena, the optical patterns can be conveniently controlled by weak optical probes and hence hold promise for applications in low-intensity optical switching [20,23,[30][31][32][33][34].We consider in this paper the pattern dynamics supported by the exciton-polariton field in a semiconductor quantum-well microcavity. Numerical simulations of these optical patterns, by directly solving the appropriate dynamical field equations, serve as the validating link between basic physical models and experiments. Nevertheless, the simulation models are usually too complex to allow easy gleaning of intuitive insight into the mechanisms of pattern competition and control. For better understanding, it would be helpful to construct models that are sufficiently flexible to capture, albeit qualitatively, the essential physics of the full simulation models and, at the same time, sufficiently simple ...

show abstract

Section: Introductionmentioning

confidence: 99%

A population-competition model for analyzing transverse optical patterns including optical control and structural anisotropy

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Many nonlinear optical media display modulational instability patterns in the optical field propagating through them. Examples include lasers, [1][2][3][4] Kerr media and optical parametric oscillators, [5][6][7] atomic gases, [8][9][10][11][12] photorefractive crystals, [13] and liquid crystal light valves, [14,15]. These instabilities are typically triggered by phase-conjugate wave mixing [16], and some common examples of patterns are stripes and hexagons.…”

Section: Introductionmentioning

confidence: 99%

Optical switching of polariton density patterns in a semiconductor microcavity

et al. 2017

View full text Add to dashboard Cite

Phase-conjugate scattering can trigger modulational instabilities in a fluid of exciton-polaritons created in a pumped semiconductor quantum-well microcavity. These instabilities can settle into density patterns, e.g. hexagons and stripes, which produce corresponding patterns in the emitted light. The density patterns can be switched by relatively weak control optical beams. This paper reviews progress in our theoretical understanding of the physical processes that regulate the competitions among various patterns and drive the optical switching. Simulation results of pattern switching using a microscopic model of polariton dynamics are shown, and the mechanisms underlying competitions and switching are analyzed using reduced models that restrict the polariton motions to a limited number of relevant modes. We also briefly indicate the effects of the spin dependence of the polariton dynamics on the patterns.

show abstract

“…The nanodispersion of alkali metals into porous glass materials is one of the most straightforward strategies that can access nonlinear optical physics [1][2][3][4][5] and reduction chemistry [6][7][8] as well as high-density energy storage applications. 9) Nonlinear optical properties dependent on the cluster size and shape of alkali metals have been reported for nanoporous silica, which possesses a random interconnected network of elongated pores with a mean diameter of 17 nm.…”

Section: Introductionmentioning

confidence: 99%

Study of Alkali-Metal Vapor Diffusion into Glass Materials

Sato¹

2013

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

To investigate nanodispersion of alkali metals into glass materials, potassium vapor diffusion is conducted using SiO2 glass under well-controlled temperature conditions. It is found that potassium vapor significantly diffuses into the bulk of SiO2 glass with less precipitation on the surface when the host material is kept at a temperature slightly higher than that of the guest material. Positron annihilation spectroscopy reveals that angstrom-scale open spaces in the SiO2 matrix contribute to potassium vapor diffusion. The analysis of potassium concentration obtained by electron probe microanalysis (EPMA) mapping with Fick's second law yields an extremely low potassium diffusion coefficient of 5.1×10-14 cm2 s-1, which arises from the overall diffusion from open spaces of various sizes. The diffusion coefficient attributable to angstrom-scale open spaces is thus expected to be less than ∼10-14 cm2 s-1. The present findings imply that angstrom-scale open spaces play an important role in loading alkali metals into glass materials.

show abstract

Secondary bifurcations of hexagonal patterns in a nonlinear optical system: Alkali metal vapor in a single-mirror arrangement

Cited by 9 publications

References 34 publications

A population-competition model for analyzing transverse optical patterns including optical control and structural anisotropy

A population-competition model for analyzing transverse optical patterns including optical control and structural anisotropy

Optical switching of polariton density patterns in a semiconductor microcavity

Study of Alkali-Metal Vapor Diffusion into Glass Materials

Contact Info

Product

Resources

About