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ABSTRACT: We investigate the potential of transformation optics for the design of novel
electromagnetic cavities. First, we determine the dispersion relation of bound
modes in a device performing an arbitrary radial coordinate transformation and
we discuss a number of such cavity structures. Subsequently, we generalize our
study to media that implement azimuthal transformations and we show that such
transformations can manipulate the azimuthal mode number. Finally, we discuss
how the combination of radial and azimuthal coordinate transformations allows
for perfect confinement of subwavelength modes inside a cavity consisting of
right-handed materials only.
08/2011;
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ABSTRACT: We use transformation optics to design an optical cavity that allows for the subwavelength confinement of light. Our cavity combines a deep subwavelength mode volume with the absence of intrinsic (bending) losses.
Lasers and Electro-Optics (CLEO) and Quantum Electronics and Laser Science Conference (QELS), 2010 Conference on; 06/2010
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ABSTRACT: In order to investigate the size limit on spatial localized structures in a nonlinear system, we explore the impact of linear nonlocality on their domains of existence and stability. Our system of choice is an optical microresonator containing an additional metamaterial layer in the cavity, allowing the nonlocal response of the material to become the dominating spatial process. In that case, our bifurcation analysis shows that this nonlocality imposes a new limit on the width of localized structures going beyond the traditional diffraction limit. Comment: 4 pages, 4 figures
12/2009;
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ABSTRACT: We demonstrate that it is possible to confine electromagnetic radiation in cavities that are significantly smaller than the wavelength of the radiation it encapsulates. To this aim, we use the techniques of transformation optics. First, we present a "perfect cavity" of arbitrarily small size in which such confined modes can exist. Furthermore, we show that these eigenmodes have a continuous spectrum and that bending losses are absent, in contrast to what is observed in traditional microcavities. Finally, we introduce an alternative cavity configuration that is less sensitive to material imperfections and still exhibits deep subwavelength modes combined with high quality factor, even if considerable material losses are included. Such a cavity may be interesting for the storage of information in optical data processing and for applications in quantum optics. Comment: 5 pages, 4 figures
11/2009;
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ABSTRACT: This study demonstrates a metamaterial with two coupled split-ring resonators (SRR) can exhibit an effect reminiscent of electromagnetically induced transparency (EIT), a coherent process normally observed in three-level atomic media. The coupling between two SRR induces a frequency splitting in the spectral response of the metamaterial, opening up a narrow transmission band in the centre of the absorption line. The obtained reduction in group velocity together with the low absorption is useful for a variety of slow-light applications, without the need for the extreme cooling or the large magnetic fields that are typically required for EIT in atomic systems.
Lasers and Electro-Optics 2009 and the European Quantum Electronics Conference. CLEO Europe - EQEC 2009. European Conference on; 07/2009
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ABSTRACT: We demonstrate theoretically that electromagnetically induced transparency can be achieved in metamaterials, in which electromagnetic radiation is interacting resonantly with mesoscopic oscillators rather than with atoms. We describe novel metamaterial designs that can support a full dark resonant state upon interaction with an electromagnetic beam and we present results of its frequency-dependent effective permeability and permittivity. These results, showing a transparency window with extremely low absorption and strong dispersion, are confirmed by accurate simulations of the electromagnetic field propagation in the metamaterial.
Physical Review Letters 03/2009; 102(5):053901. · 7.37 Impact Factor
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ABSTRACT: We propose a slab waveguide structure containing a left-handed material. The thickness of this waveguide can be reduced below one wavelength, with light still excellently confined to its core.
Optical Communication, 2008. ECOC 2008. 34th European Conference on; 10/2008
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ABSTRACT: A basic rate equation model of a quantum-well semiconductor ring laser is reduced to two equations using asymptotic methods. The reduced model allows for analytical expressions of the bifurcation points, which will simplify future model parameter estimations, and motivates a two-dimensional phase-space description of the dynamical behaviour. An analysis of the bifurcation scenarios in different parameter regimes is pursued. Physical conditions for the emergence of the operating regimes are assessed quantitatively in terms of saturation processes and backscattering mechanisms.
J. Phys. B: At. Mol. Opt. Phys. 01/2008; 41.
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ABSTRACT: In this contribution, we want to investigate the influence of left-handed materials on the spatiotemporal dynamics of degenerate optical parametric oscillators, which use a quadratic crystal to convert the energy of a pump laser to a signal field at half the pump frequency. It is well known that the coupling between diffraction and nonlinearity in such devices can induce a modulational instability in the homogeneous output beam, leading to the formation of dissipative structures. However, the inclusion of a left-handed material dramatically changes this dynamical behaviour.
Lasers and Electro-Optics, 2007 and the International Quantum Electronics Conference. CLEOE-IQEC 2007. European Conference on; 07/2007
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ABSTRACT: Recent advances in the field of left-handed materials (LHM) have renewed the interest for the study of the propagation properties in these materials. In particular, many works have been devoted to the study of the Veselago plate, which constitutes the simplest linear system based on LHM. Recently, Zharov and co-workers introduced a description of the nonlinear properties of LHM. In particular, they suggested that LHM could be used as the basis of power limiters, all optical switches, etc. In this communication, we consider a Fabry-Perot cavity filled with two materials having refractive indexes of opposite signs, and driven by an external coherent field. Using the well-known mean-field approximation, we derive a partial differential equation describing the bidirectional propagation of light in this optical cavity. In the absence of reflection at the interface between the LHM and the RHM, our model is similar to the well-known LL-model. However, an important difference that appears when considering LHM is that the sign of the diffraction term can be reversed by varying the geometry. Besides the bistable behaviour of the homogeneous response curve of the system, our study reveals the existence of modulational instability. The wavelength of the spatial dissipative structure emerging from that instability can be tuned continuously by varying the diffraction coefficient.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
09/2005;
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ABSTRACT: Cavity solitons are controllable two-dimensional transverse Localized Structures (LS) in dissipative optical cav-ities. Such LS have been suggested for use in optical data storage and information processing. Typically, diffraction constrains the size of these light spots to be of the order of the square root of the diffraction coeffi-cient of the system. Due to recent advances in the development of metamaterials, the diffraction strength in a cavity could be controlled by adding a left-handed material layer in a Fabry-Perot resonator together with a tra-ditional nonlinear material. This system thus potentially allows for LS beyond the size limit imposed by natural diffraction. However, when the diffraction strength becomes smaller, the non-local response of the left-handed metamaterial starts to dominate the nonlinear spatiotemporal dynamics. Considering a typical linear non-local response, we develop a mean-field model describing the spatiotemporal evolution of LS. First, the influence of this non-local response on the minimal attainable width of the LS is studied [Gelens et al., Phys. Rev. A 75, 063812 (2007)]. Secondly, we elaborate on the different possible mechanisms that can destabilize the LS, leading to stable oscillations, expanding patterns, or making the LS disappear. Furthermore, we also show multiple routes towards excitability present in the system. We demonstrate that these different regions admitting stationary, oscillating or excitable LS unfold from two Takens-Bogdanov codimension-2 points [Gelens et al., Phys. Rev. A 77 (2008)].
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ABSTRACT: We study Veselago’s lens with arbitrary index of refraction and characteristic impedance. Using a full wave optics calculation, we show that this lens can be considered as an imaging system and we derive the appropriate lens formula. The lens with arbitrary index and impedance retains some of the properties of the matched lens, such as the invariance of its optical axis, three-dimensional imaging and easy manufacturing, but it loses the property of sub-wavelength resolution. We also show that identical results can be obtained for the impedance matched lens in the framework of paraxial geometrical optics, from which it can be inferred that optical systems containing such a lens can be studied and designed using traditional ray-tracing tools.
Optics Communications.
