Roadmap on optical rogue waves and extreme events

Abstract

The pioneering paper 'Optical rogue waves' by Solli et al (2007 Nature 450 1054) started the new subfield in optics. This work launched a great deal of activity on this novel subject. As a result, the initial concept has expanded and has been enriched by new ideas. Various approaches have been suggested since then. A fresh look at the older results and new discoveries has been undertaken, stimulated by the concept of 'optical rogue waves'. Presently, there may not by a unique view on how this new scientific term should be used and developed. There is nothing surprising when the opinion of the experts diverge in any new field of research. After all, rogue waves may appear for a multiplicity of reasons and not necessarily only in optical fibers and not only in the process of supercontinuum generation. We know by now that rogue waves may be generated by lasers, appear in wide aperture cavities, in plasmas and in a variety of other optical systems. Theorists, in turn, have suggested many other situations when rogue waves may be observed. The strict definition of a rogue wave is still an open question. For example, it has been suggested that it is defined as 'an optical pulse whose amplitude or intensity is much higher than that of the surrounding pulses'. This definition (as suggested by a peer reviewer) is clear at the intuitive level and can be easily extended to the case of spatial beams although additional clarifications are still needed. An extended definition has been presented earlier by N Akhmediev and E Pelinovsky (2010 Eur. Phys. J. Spec. Top. 185 1-4). Discussions along these lines are always useful and all new approaches stimulate research and encourage discoveries of new phenomena. Despite the potentially existing disagreements, the scientific terms 'optical rogue waves' and 'extreme events' do exist. Therefore coordination of our efforts in either unifying the concept or in introducing alternative definitions must be continued. From this point of view, a number of the scientists who work in this area of research have come together to present their research in a single review article that will greatly benefit all interested parties of this research direction. Whether the authors of this 'roadmap' have similar views or different from the original concept, the potential reader of the review will enrich their knowledge by encountering most of the existing views on the subject. Previously, a special issue on optical rogue waves (2013 J. Opt. 15 060201) was successful in achieving this goal but over two years have passed and more material has been published in this quickly emerging subject. Thus, it is time for a roadmap that may stimulate and encourage further research.

Generation of extreme pulses on demand in semiconductor lasers with optical injection

“…Laser systems displaying extreme optical pulses, often referred to as optical rogue waves (RWs) [1], are being intensively investigated as they are excellent test beds to study extreme fluctuations under controlled conditions [2][3][4][5][6][7][8][9]. Rogue waves have been observed in many systems and were initially found in hydrodynamics, where occasionally, huge waves in ocean waters have been reported that, in contrast to tsunamis or solitons, can appear from nowhere, disappear in a short spatial length and do not necessarily propagate for long distances [10].…”

“…Optical rogue waves have also been investigated in laser models that include spatial degrees of freedom (one or two dimensions) [9]. While in these models extreme pulses might still be generated by a similar mechanism as in the rate-equation model (the presence of a narrow-channel or a "RW door" in the phase space), due to the high-dimensionality of the phase space this special region is difficult to identify.…”

“…While in these models extreme pulses might still be generated by a similar mechanism as in the rate-equation model (the presence of a narrow-channel or a "RW door" in the phase space), due to the high-dimensionality of the phase space this special region is difficult to identify. In addition, in the presence of spatial degrees of freedom, several other features can be relevant for understanding the RW phenomenon [9,[19][20][21].…”

Optical Peregrine rogue waves of self-induced transparency in a resonant erbium-doped fiber

“…Rogue wave research flourishes now in both theoretical and experimental aspects [10,12,14], providing novel perspectives for the manifestation of extreme waves in a variety of nonlinear media. To reflect the diversity and complexity of media, it requires the study of the propagation models that go beyond the scalar nonlinear Schrödinger (NLS) equation, such as the extended scalar models [15][16][17][18] and the coupled multicomponent models [19][20][21][22][23][24][25].…”

Weak Langmuir optical turbulence in a fiber cavity

“…The propagation of partially coherent nonlinear optical waves is a subject of growing interest in different fields of investigations, such as, e.g., supercontinuum (SC) generation [1,2], rogue waves [3][4][5][6], shock waves [7][8][9], nonlinear interferometry [10,11], or incoherent wave propagation in homogeneous [12][13][14][15][16], discrete [17], multimode [18,19] and single-mode fibers nearby the integrable limit [20][21][22]. From a different perspective, optical cavities and lasers offer an interesting experimental platform to study different regimes of optical turbulence [12,[23][24][25][26][27][28][29][30][31][32][33][34][35][36][37].…”