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Laudyn UA, Kwasny M, Piccardi A, Karpierz MA, Dabrowski R, Chojnowska O, Alberucci A, Assanto G. Nonlinear competition in nematicon propagation. Opt Lett 2015; 40:5235-5238. [PMID: 26565843 DOI: 10.1364/ol.40.005235] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We investigate the role of competing nonlinear responses in the formation and propagation of bright spatial solitons. We use nematic liquid crystals (NLCs) exhibiting both thermo-optic and reorientational nonlinearities with continuous-wave beams. In a suitably prepared dye-doped sample and dual beam collinear geometry, thermal heating in the visible affects reorientational self-focusing in the near infrared, altering light propagation and self-trapping.
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2
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Yang X, Chen W, Yao P, Zhang T, Tian J, Xu J. Observation of surface dark photovoltaic solitons. Opt Express 2013; 21:4783-4789. [PMID: 23482012 DOI: 10.1364/oe.21.004783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Surface dark solitons in photovoltaic nonlinear media are reported. Taking advantage of diffusion and photovoltaic nonlinearities we demonstrated the surface dark solitons and their behaviors near surface theoretically and experimentally in LiNbO₃ crystal. It is very interesting that surface dark soliton is just half of dark soliton in bulk. Another interesting thing is that transverse modulation instability can be perfectly suppressed by surface dark soliton in virtue of surface. In addition, surface waveguides were written successfully utilizing surface dark soliton.
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Affiliation(s)
- Xi Yang
- Photonics Research Center, School of Physics, the MOE Key Lab of Weak-Light Nonlinear Photonics, and Tianjin Key Laboratory of Photonics Materials and Technology for Information Science, Nankai University, Tianjin 300071, China.
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3
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Lahav O, Gurgov H, Sidorenko P, Peleg O, Levi L, Fleischer A, Cohen O. Self-phase modulation spectral broadening in two-dimensional spatial solitons: toward three-dimensional spatiotemporal pulse-train solitons. Opt Lett 2012; 37:5196-5198. [PMID: 23258050 DOI: 10.1364/ol.37.005196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We demonstrate self-phase modulation (SPM) spectral broadening in two-dimensional solitons in homogeneous media using two different schemes. In the active mode, a train of pulses are collectively trapped and form a spatial soliton through a photorefractive, slowly responding, and electronically controlled self-focusing nonlinearity, and each pulse experiences spectral broadening by the fast SPM nonlinearity. In the passive mode, the pulse-train beam is guided in a waveguide that is optically induced by a continuous-wave thermal spatial soliton. The soliton formation increased the normalized spectral broadening factor from 0.5% up to 197%. This experiment presents significant progress toward the experimental demonstration of three-dimensional spatiotemporal pulse-train solitons.
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Affiliation(s)
- Oren Lahav
- Solid State Institute and Physics Department, Technion—Israel Institute of Technology, Haifa 32000, Israel.
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Abstract
Solitons, nonlinear self-trapped wavepackets, have been extensively studied in many and diverse branches of physics such as optics, plasmas, condensed matter physics, fluid mechanics, particle physics and even astrophysics. Interestingly, over the past two decades, the field of solitons and related nonlinear phenomena has been substantially advanced and enriched by research and discoveries in nonlinear optics. While optical solitons have been vigorously investigated in both spatial and temporal domains, it is now fair to say that much soliton research has been mainly driven by the work on optical spatial solitons. This is partly due to the fact that although temporal solitons as realized in fiber optic systems are fundamentally one-dimensional entities, the high dimensionality associated with their spatial counterparts has opened up altogether new scientific possibilities in soliton research. Another reason is related to the response time of the nonlinearity. Unlike temporal optical solitons, spatial solitons have been realized by employing a variety of noninstantaneous nonlinearities, ranging from the nonlinearities in photorefractive materials and liquid crystals to the nonlinearities mediated by the thermal effect, thermophoresis and the gradient force in colloidal suspensions. Such a diversity of nonlinear effects has given rise to numerous soliton phenomena that could otherwise not be envisioned, because for decades scientists were of the mindset that solitons must strictly be the exact solutions of the cubic nonlinear Schrödinger equation as established for ideal Kerr nonlinear media. As such, the discoveries of optical spatial solitons in different systems and associated new phenomena have stimulated broad interest in soliton research. In particular, the study of incoherent solitons and discrete spatial solitons in optical periodic media not only led to advances in our understanding of fundamental processes in nonlinear optics and photonics, but also had a very important impact on a variety of other disciplines in nonlinear science. In this paper, we provide a brief overview of optical spatial solitons. This review will cover a variety of issues pertaining to self-trapped waves supported by different types of nonlinearities, as well as various families of spatial solitons such as optical lattice solitons and surface solitons. Recent developments in the area of optical spatial solitons, such as 3D light bullets, subwavelength solitons, self-trapping in soft condensed matter and spatial solitons in systems with parity-time symmetry will also be discussed briefly.
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Affiliation(s)
- Zhigang Chen
- Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132, USA
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Peccianti M, Pasquazi A, Assanto G, Morandotti R. Enhancement of third-harmonic generation in nonlocal spatial solitons. Opt Lett 2010; 35:3342-3344. [PMID: 20967060 DOI: 10.1364/ol.35.003342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report on the observation of Type I third-harmonic generation induced by a train of femtosecond laser pulses in nematic liquid crystals. We find that as the average power of the train is increased, the frequency conversion process is enhanced as a consequence of the tight confinement of the pulses into a nonlocal spatial soliton.
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Affiliation(s)
- M Peccianti
- INRS Énergie, Matériaux et Télécommunications, 1650 Boulevard Lionel Boulet, Varennes Québec, J3X 1S2 Canada.
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Kang HZ, Zhang TH, Ma HH, Lou CB, Liu SM, Tian JG, Xu JJ. Giant enhancement of surface second-harmonic generation using photorefractive surface waves with diffusion and drift nonlinearities. Opt Lett 2010; 35:1605-1607. [PMID: 20479823 DOI: 10.1364/ol.35.001605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Giant enhancement of second-harmonic generation (SHG) with 83.4%/W coversion efficiency is obtained, taking advantage of photorefractive surface waves with diffusion and drift nonlinearity. In this method, the self-bending induced by diffusion nonlinearity can be utilized at the surface and can solve the phase-mismatch problem in bulk due to beam self-bending. With drift nonlinearity, an applied external electric filed and background illumination can further constringe surface waves to the surface and consequently enhance SHG, which provides the possibility and flexibility of control.
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Affiliation(s)
- H Z Kang
- Photonics Research Center, the MOE Key Lab of Weak-Light Nonlinear Photonics, and Tianjin Key Lab of PhotonicsMaterials and Technology for Information Science, Nankai University, Tianjin, China, 300071
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7
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Tiemann M, Schmidt J, Petrov VM, Petter J, Tschudi T. Information throughput of photorefractive spatial solitons in the telecommunication range. Appl Opt 2007; 46:2683-7. [PMID: 17446918 DOI: 10.1364/ao.46.002683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Photorefractive spatial solitons are attractive elements because they can be used as controllable optical interconnectors for all-optical devices. To our knowledge, until now their properties were investigated in terms of energy transportation. We suggest considering photorefractive spatial solitons as optically induced information channels. The experimental technique to measure the information throughput of photorefractive spatial solitons in accordance with Shannon's definition was developed and demonstrated by us. We experimentally demonstrated that in the wavelength range of 1520-1630 nm it can be estimated as large as approximately 90 Tbits/s. We also experimentally demonstrate a measurement of the group-velocity dispersion and show the limitation of the pulse transfer rate of the induced waveguides to approximately 6.2 THz.
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Affiliation(s)
- M Tiemann
- Institute of Applied Physics, Darmstadt University of Technology, Germany.
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Medhekar S, Sarkar RK, Paltani PP. Coupled spatial-soliton pairs in saturable nonlinear media. Opt Lett 2006; 31:77-9. [PMID: 16419883 DOI: 10.1364/ol.31.000077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We present a simple and straightforward approach to investigate coupled spatial-soliton pairs of two copropagating mutually incoherent (i.e., both beams are fully spatially and temporally coherent, but are incoherent with respect to one another) light beams in saturable nonlinear media. The approach provides a deeper understanding of coupled spatial-soliton pairs and reveals many interesting features, including the entire existence curve of such solitons.
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Affiliation(s)
- S Medhekar
- Department of Applied Physics, Birla Institute of Technology, Mesra, Ranchi-835215, India.
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DelRe E, Ciattoni A, Palange E. Role of charge saturation in photorefractive dynamics of micron-sized beams and departure from soliton behavior. Phys Rev E Stat Nonlin Soft Matter Phys 2006; 73:017601. [PMID: 16486315 DOI: 10.1103/physreve.73.017601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Indexed: 05/06/2023]
Abstract
Experimental and theoretical results indicate that miniaturized micron-sized nonlinear beam phenomenology in photorefractives leads to a regime qualitatively distinct from solitonlike propagation on consequence of the specific role of space-charge saturation. In the highly modulated conditions typical of beams, this contribution amounts to an effective electron self-action.
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Affiliation(s)
- E DelRe
- Laboratorio di Ottica e Fotonica, Dipartimento di Ingegneria Elettrica, Università dell'Aquila, Monteluco di Roio 67040 L'Aquila, Italy.
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Delre E, D'Ercole A, Palange E. Mechanisms supporting long propagation regimes of photorefractive solitons. Phys Rev E Stat Nonlin Soft Matter Phys 2005; 71:036610. [PMID: 15903608 DOI: 10.1103/physreve.71.036610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2004] [Indexed: 05/02/2023]
Abstract
We extend investigation of one-dimensional solitons in biased photorefractive crystals to long propagation regimes, where self-trapping over a large number of linear diffraction lengths combines with the progressive growth of generally distortive spatially nonlocal components. Results indicate that saturation halts the radiative misshaping of the soliton, which follows that specific bending trajectory along which its evolution is governed by the same local screening nonlinearity that intervenes in short propagation conditions, where spatial nonlocality has a negligible effect. This finding not only allows the prediction of the curvature and of the relative role of charge displacement and diffusion, but implies a set of interesting observable effects, such as boomerangs, counterpropagating and cavity geometries, quasirectilinear and anomalous collisions, along with specific consequences on soliton arrays and on coupling to bulk gratings.
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Affiliation(s)
- Eugenio Delre
- Dipartimento di Fisica, Università dell'Aquila, Italy.
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Lou C, Xu J, Qiao H, Zhang X, Chen Y, Chen Z. Enhanced second-harmonic generation by means of high-power confinement in a photovoltaic soliton-induced waveguide. Opt Lett 2004; 29:953-955. [PMID: 15143638 DOI: 10.1364/ol.29.000953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We present the first experimental demonstration of enhanced second-harmonic generation (SHG) by means of power confinement with a femtosecond laser in a photovoltaic soliton-induced waveguide. A dark spatial soliton created with a weak cw laser beam in a photovoltaic lithium niobate crystal induces an efficient waveguide for SHG, leading to a 60% enhancement of the conversion efficiency.
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Affiliation(s)
- Cibo Lou
- TEDA Applied Physics School, Photonics Center, College of Physics Science, Nankai University, Tianjin, China
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12
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Salgueiro JR, Carlsson AH, Ostrovskaya E, Kivshar Y. Second-harmonic generation in vortex-induced waveguides. Opt Lett 2004; 29:593-595. [PMID: 15035481 DOI: 10.1364/ol.29.000593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We study the second-harmonic generation and localization of light in a reconfigurable waveguide induced by an optical vortex soliton in a defocusing Kerr medium. We show that the vortex-induced waveguide greatly improves conversion efficiency from the fundamental to the second-harmonic field.
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Affiliation(s)
- José R Salgueiro
- Nonlinear Physics Group, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200, Australia.
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Chen Z, Asaro M, Ostroverkhova O, Moerner WE, He M, Twieg RJ. Self-trapping of light in an organic photorefractive glass. Opt Lett 2003; 28:2509-2511. [PMID: 14690130 DOI: 10.1364/ol.28.002509] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We report the first observation, to our knowledge, of self-trapping of light as well as optically induced focusing-to-defocusing switching in an organic photorefractive glass, owing to the orientationally enhanced photorefractive nonlinearity of the material.
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Affiliation(s)
- Zhigang Chen
- Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132, USA.
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Delre E, Crosignani B, Di Porto P, Palange E, Agranat AJ. Electro-optic beam manipulation through photorefractive needles. Opt Lett 2002; 27:2188-2190. [PMID: 18033478 DOI: 10.1364/ol.27.002188] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We demonstrate electro-optic spatial two-dimensional mode switching in a bulk sample of potassium lithium tantalate niobate. Spatial confinement, mode coupling, and electro-optic functionality are mediated by two photorefractive needle solitons of opposite electroholographic charges embedded together in their anisotropic lobular structure.
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Abstract
We report what is to our knowledge the first observation of pixellike spatial solitons from partially spatially incoherent light. We created an array of as many as 32x32 soliton pixels by launching a spatially modulated incoherent light beam into a noninstantaneous self-focusing photorefraction medium. These solitons were stable and robust, forming a steady-state two-dimensional waveguide array in which optical coupling and control of local waveguide channels could be realized.
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Schwartz T, Ganor Y, Carmon T, Uzdin R, Shwartz S, Segev M, El-Hanany U. Photorefractive solitons and light-induced resonance control in semiconductor CdZnTe. Opt Lett 2002; 27:1229-1231. [PMID: 18026411 DOI: 10.1364/ol.27.001229] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We demonstrate the formation of (1+1) - and (2+1) -dimensional solitons in photorefractive CdZnTe:V, exploiting the intensity-resonant behavior of the space-charge field. We control the resonance optically, facilitating a 10-mus soliton formation times with very low optical power.
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Abstract
We demonstrate experimentally an optical parametric oscillator constructed in a waveguide induced by a photorefractive spatial soliton and show that the pumping threshold is reduced considerably.
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Johansen SK, Bang O, Sørensen MP. Escape angles in bulk chi((2)) soliton interactions. Phys Rev E Stat Nonlin Soft Matter Phys 2002; 65:026601. [PMID: 11863672 DOI: 10.1103/physreve.65.026601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2000] [Revised: 09/10/2001] [Indexed: 05/23/2023]
Abstract
We develop a theory for nonplanar interaction between two identical type I spatial solitons propagating at opposite, but arbitrary transverse angles in quadratic nonlinear (or so-called chi((2))) bulk media. We predict quantitatively the outwards escape angle, below which the solitons turn around and collide, and above which they continue to move-away from each other. For in-plane interaction, the theory allows prediction of the outcome of a collision through the inwards escape angle, i.e., whether the solitons fuse or cross. We find an analytical expression determining the inwards escape angle using Gaussian approximations for the solitons. The theory is verified numerically.
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Affiliation(s)
- Steffen Kjaer Johansen
- Department of Informatics and Mathematical Modeling, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
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Guo A, Henry M, Salamo GJ, Segev M, Wood GL. Fixing multiple waveguides induced by photorefractive solitons: directional couplers and beam splitters. Opt Lett 2001; 26:1274-1276. [PMID: 18049584 DOI: 10.1364/ol.26.001274] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We show how to transform multiple real-time photorefractive solitons into permanent two-dimensional single-mode waveguides impressed into the crystalline lattice of the host material. We experimentally demonstrate two specific configurations of such fixed multiple waveguides: directional couplers and multiple beam splitters.
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Sassa T, Wada T, Sasabe H, Yokoyama M, Umegaki S. Active formation of an antiguide structure in a photorefractive polymer for enhanced second-harmonic generation. Opt Lett 2001; 26:995-997. [PMID: 18040512 DOI: 10.1364/ol.26.000995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
An antiguide structure for enhanced second-harmonic generation was actively constructed in a photorefractive polymer by use of a pump beam. Irradiation of a pump beam enhanced second-harmonic power, and blocking the pump returned the power to the initial value. The electric-field dependence of the degree of enhancement of the second-harmonic power confirmed that the antiguide structure was constructed through a photorefractive-index change in the medium. The photorefractive-index change accompanied molecular reorientation induced by the pump-generated space charges. The thermo-optic effect on formation of the structure is also discussed.
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Abstract
The combination of charge separation induced by the formation of a single photorefractive screening soliton and an applied external bias field in a paraelectric is shown to lead to a family of useful electro-optic guiding patterns and properties.
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Abstract
We demonstrate experimentally optical guidance of coherent light beams, using incoherent light. Such guidance is made possible by generation of partially spatially incoherent self-trapped dark beams (dark incoherent solitons) in a noninstantaneous nonlinear medium. In the one-dimensional case, the incoherent solitons induce single and Y-junction planar waveguides, whereas in the two-dimensional case, they form circular waveguides. These experiments introduce the possibility of controlling high-power laser beams with low-power incoherent light sources such as LED's or lightbulbs.
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