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Related papers: Spectral Singularities and a New Method of Generat…

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In our earlier work on harmonic generation with complex light [Nature Communications 15, 6878 (2024)], we demonstrated how the harmonic spectrum of a complex laser beam in a nonlinear medium can be obtained through the judicious application…

Optics · Physics 2025-11-17 Raoul Trines , Holger Schmitz , Martin King , Paul McKenna , Robert Bingham

Spectral singularities are certain points of the continuous spectrum of generic complex scattering potentials. We review the recent developments leading to the discovery of their physical meaning, consequences, and generalizations. In…

Quantum Physics · Physics 2015-04-07 Ali Mostafazadeh

The resonant state expansion, a recently developed method in electrodynamics, is generalized here to planar open optical systems with non-normal incidence of light. The method is illustrated and verified on exactly solvable examples, such…

Optics · Physics 2015-05-05 L. J. Armitage , M. B. Doost , W. Langbein , E. A. Muljarov

Tunable narrowband spectral filters with high light throughput and wide dynamic range have remarkable applications such as in optical communications, optical spectroscopy and spectral imaging. However, a cost is usually associated with the…

Optics · Physics 2018-10-24 Ibrahim Abdulhalim

We propose and theoretically investigate integrated photonic filters based on coupled Sagnac loop reflectors (SLRs) formed by a self-coupled wire waveguide. By tailoring coherent mode interference in the device, three different filter…

Optics · Physics 2021-06-10 David J. Moss

There are several mechanisms by which the frequency spectrum of a laser broadens when it propagates at near-relativistic-intensity in tenuous plasma. Focusing on one dimensional effects, we identify two strong optical nonlinearities,…

Plasma Physics · Physics 2021-09-22 Kenan Qu , Nathaniel J. Fisch

We use blow-up solutions of nonlinear Helmholtz equations to introduce a nonlinear resonance effect that is capable of amplifying electromagnetic waves of particular intensity. To achieve this, we propose a scattering setup consisting of a…

Optics · Physics 2019-01-28 Ali Mostafazadeh , Hamed Ghaemi-Dizicheh , Sasan Hajizadeh

A design methodology for planar loaded antenna arrays is proposed to synthesize a perfect anomalous reflection into an arbitrary direction by optimizing the scattering characteristics of passively loaded array antennas. It is based on…

Applied Physics · Physics 2024-09-26 Sravan K. R. Vuyyuru , Risto Valkonen , Sergei A. Tretyakov , Do-Hoon Kwon

Nonlinear optics is crucial for shaping the spatial structure of shortwave light and its interactions with matter, but achieving this through simple harmonic generation with a single pump is challenging. This study demonstrates nonlinear…

Optics · Physics 2025-06-23 Ting-Ting Liu , Shi-Hui Ding , Chun-Yu Li , Hui Liu , Zhi-Han Zhu , Peng Chen , Yan-Qing Lu

We extend the angular power density formulae for spontaneous radiation emission from planar undulators to include finite emittance and angular misalignment of the electron beam. Then we calculate and compare power densities estimated from…

Accelerator Physics · Physics 2025-05-01 Ganesh Tiwari , Timur Shaftan

A phase retrieval technique using a spatial light modulator (SLM) and a phase diffuser for a fast reconstruction of smooth wave fronts is demonstrated experimentally. Diffuse illumination of a smooth test object with the aid of a phase…

Optics · Physics 2015-06-11 Mostafa Agour , Percival F. Almoro , Claas Falldorf

This paper presents a new linear hyperspectral unmixing method of the minimum volume class, termed \emph{simplex identification via split augmented Lagrangian} (SISAL). Following Craig's seminal ideas, hyperspectral linear unmixing amounts…

Optimization and Control · Mathematics 2016-11-17 Jose Bioucas-Dias

There has been a rapidly growing interest in optoelectronic properties of graphene and associated structures. Despite the general belief on absence of spontaneous emission in graphene, which is normally attributed to its unique ultrafast…

Mesoscale and Nanoscale Physics · Physics 2015-09-30 Sina Khorasani

We demonstrate a wavelength spacing tunable, multiwavelength Q-switched mode-locked fiber laser (QML) based on a fiber taper deposited with graphene oxide. The operation of the laser can be understood in terms of the formation of bunches of…

Optics · Physics 2014-09-29 Lei Gao , Tao Zhu

We report an approach for high-resolution spectroscopy using a widely tunable laser emitting in the molecular fingerprint region. The laser is based on difference-frequency generation (DFG) in a nonlinear orientation-patterned GaAs crystal.…

A mechanism for electrically tunable PT-symmetric magnonic lasing and anti-lasing is proposed along with a device consisting of a current-biased region in a magnetically ordered planar waveguide. Within the bias area, several heavy-metal…

Strongly Correlated Electrons · Physics 2025-11-18 Xi-guang Wang , Tian-xiang Lu , Guang-hua Guo , Jamal Berakdar , Hui Jing

Surface-enhanced Raman spectroscopy (SERS) allows single-molecule detection due to the strong field localization occurring at sharp bends or kinks of the metal-vacuum interface. An important question concerns the limits of the signal…

Optics · Physics 2008-06-19 Sanshui Xiao , Niels Asger Mortensen , Antti-Pekka Jauho

Unidirectional radiation is important for a variety of optoelectronic applications. Many unidirectional emitters exist, but they all rely on the use of materials or structures that forbid outgoing waves, i.e. mirrors. Here, we theoretically…

Optics · Physics 2019-06-25 Xuefan Yin , Jicheng Jin , Marin Soljačić , Chao Peng , Bo Zhen

Sum-frequency generation (SFG) spectroscopy provides a versatile method for the investigation of non-centrosymmetric media and interfaces. Here, using tunable picosecond infrared (IR) pulses from a free-electron laser, the nonlinear optical…

Materials Science · Physics 2023-08-01 Riko Kiessling , Martin Wolf , Alexander Paarmann

Emission of photon pairs by metal-dielectric interface in case of a superluminally propagating laser-induced nonlinear polarization is considered. Using oblique incidence of the laser wave it is possible to tune frequencies of generated…

Mesoscale and Nanoscale Physics · Physics 2014-05-15 Vladimir Hizhnyakov
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