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The threshold properties of photonic crystal quantum dot lasers operating in the slow-light regime are investigated experimentally and theoretically. Measurements show that, in contrast to conventional lasers, the threshold gain attains a…

In conventional lasers, the optical cavity that confines the photons also determines essential characteristics of the lasing modes such as wavelength, emission pattern, ... In random lasers, which do not have mirrors or a well-defined…

Disordered Systems and Neural Networks · Physics 2016-09-08 Jonathan Andreasen , Ara Asatryan , Lc Botten , Michael Byrne , Hui Cao , Li Ge , Laurent Labonté , Patrick Sebbah , A. D. Stone , Hakan Türeci , Christian Vanneste

We demonstrate the capability of complete thresholdless lasing operation between dressed states of a two-level atom located inside a microscopic cavity engineered in a photonic band-gap material. We distinguish between threshold and…

Quantum Physics · Physics 2015-05-13 Gao-xiang Li , Min Luo , Zbigniew Ficek

Experiments and their interpretation on polarization dynamics and polarization switching in vertical-cavity surface-emitting lasers operated in the fundamental transverse mode regime are reviewed. Important observations are switching events…

Optics · Physics 2025-07-14 Thorsten Ackemann , Markus Sondermann

Chaos in semiconductor lasers or other optical systems has been intensively studied in the past two decades. However, modulation around threshold has received much less attention, in particular in gain-modulated semiconductor lasers. In…

Optics · Physics 2022-03-09 J. Zou , H. Zhou , C. Jiang , G. Wang , G. L. Lippi , T. Wang

The basic physics of lasers is characterized by a second-order continuous phase transition at the critical lasing threshold. Nevertheless, laser bistability with abrupt transitions has been reported in some laser systems, but its underlying…

We address the problem of achieving an optical random laser with a cloud of cold atoms, in which gain and scattering are provided by the same atoms. The lasing threshold can be defined using the on-resonance optical thickness b0 as a single…

Atomic Physics · Physics 2015-05-13 Luis S. Froufe-Pérez , William Guerin , Rémi Carminati , Robin Kaiser

Spontaneous and stimulated emission of an electron in the ion channel is studied. The emission processes are studied in the regime of high harmonic generation when the parameter of plasma wiggler strength is large. Like for conventional…

Optics · Physics 2007-05-23 I. Kostyukov , A. Pukhov

Spin effects in the tunneling regime of strong field ionization of hydrogenlike highly charged ions in linearly as well as circularly polarized laser fields are investigated. The impact of the polarization of a laser field on the spin…

Quantum Physics · Physics 2018-07-04 Enderalp Yakaboylu , Michael Klaiber , Karen Z. Hatsagortsyan

The lasing operation of a ZnO planar microcavity under optical pumping is demonstrated from T=80 K to 300 K. At the laser threshold, the cavity switches from the strong coupling to the weak coupling regime. A gain-related transition, which…

A new kind of mechanism of lasing is investigated experimentally. It is quite different from the traditional laser with cavity and the random laser with random scattering. In this mechanism, the intensity-dependent refractive index effect…

Optics · Physics 2013-06-28 Jinwei Shi , Shujing Chen , Wenjun Fan , Xiangyu Kong , Dahe Liu , Lily Zu

An experimental study of the delayed threshold phenomenon in a Vertical Extended Cavity Semiconductor Emitting Laser is carried out. Under modulation of the pump power, the laser intensity exhibits a hysteresis behavior in the vicinity of…

A spin-polarizing electron beam splitter is described which relies on an arrangement of linearly polarized laser waves of nonrelativistic intensity. An incident electron beam is first coherently scattered off a bichromatic laser field,…

Quantum Physics · Physics 2017-02-22 Matthias M. Dellweg , Carsten Müller

The realization of high-$\beta$ lasers is one of the prime applications of cavity-QED promising ultra-low thresholds, integrability and reduced power consumption in the field of \textit{green photonics}. In such nanolasers spontaneous…

Mesoscale and Nanoscale Physics · Physics 2018-12-17 Frederik Lohof , Roy Barzel , Paul Gartner , Christopher Gies

Microcavity polaritons in the lasing regime undergo a spontaneous symmetry breaking transition resulting in coherent emission with a well defined polarization. The order parameter is thus a vector describing both the laser global phase and…

Since the development of micro- and nanolasers, the question of laser threshold has been subject to debate. Different definitions have been used to try and establish its occurrence, often encountering major obstacles. We examine a set of…

Optics · Physics 2022-03-14 G. L. Lippi , T. Wang , G. P. Puccioni

We study the resonance fluorescence properties of an optically active spin 1/2 system, elucidating the effects of a magnetic field on the coherence of the scattered light. We derive a master equation model for this system that reproduces…

We show that an inhomogeneity in the spin-transfer torques in a metallic ferromagnet under suitable conditions strongly amplifies incoming spin waves. Moreover, at nonzero temperatures the incoming thermally occupied spin waves will be…

Mesoscale and Nanoscale Physics · Physics 2019-01-30 R. J. Doornenbal , A. Roldán-Molina , A. S. Nunez , R. A. Duine

Conventional lasers make use of optical cavities to provide feedback to gain media. Conversely, mirrorless lasers can be built by using disordered structures to induce multiple scattering, which increases the effective path length in the…

Atomic Physics · Physics 2015-06-12 Quentin Baudouin , Nicolas Mercadier , Vera Guarrera , William Guerin , Robin Kaiser

The effects of the initial spin orientation on the final electron beam polarization via laser wakefield acceleration in pre-polarized plasma are investigated theoretically and numerically. From a variation of the initial spin direction, the…

Plasma Physics · Physics 2025-02-13 L. R. Yin , X. F. Li , Y. J. Gu , N. Cao , Q. Kong , M. Buescher , S. M. Weng , M. Chen , Z. M. Sheng