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Related papers: Spatial coherence of random laser emission

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It is known that a spatially partially coherent light field produces better imaging contrast compared to a spatially coherent field and that the contrast increases as the spatial coherence length of the field becomes smaller. The transverse…

Weakly scattering random lasers exhibit lasing modes that spatially overlap and can interact strongly via gain saturation. Consequently, lasing in high-threshold modes may be suppressed by strong low-threshold lasing modes. We numerically…

Optics · Physics 2012-02-22 Jonathan Andreasen , Hui Cao

Spatial distributions of electrons ionized and scattered from ultra-low pressure gases are proposed and experimentally demonstrated as a method to directly measure the intensity of an ultra-high intensity laser pulse. Analytic models…

Spatial coherence quantifies spatial field correlations over time, and is one of the fundamental properties of light. Here we investigate the spatial coherence of highly multimode lasers in the regime of short time scales. Counter…

Arrays of coupled semiconductor lasers are systems possessing radically complex dynamics that makes them useful for numerous applications in beam forming and beam shaping. In this work, we investigate the spatial controllability of…

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

A numerical study is presented of one-dimensional and two-dimensional random lasers as a function of the pumping rate above the threshold for lasing. Depending on the leakiness of the cavity modes, we observe that the stationary lasing…

Optics · Physics 2011-08-17 Jonathan Andreasen , Patrick Sebbah , Christian Vanneste

We analyze the light scattered by a single InAs quantum dot interacting with a resonant continuous-wave laser. High resolution spectra reveal clear distinctions between coherent and incoherent scattering, with the laser intensity spanning…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 K. Konthasinghe , J. Walker , M. Peiris , C. K. Shih , Y. Yu , M. F. Li , J. F. He , L. J. Wang , H. Q. Ni , Z. C. Niu , A. Muller

The distribution of spacings between the lasing frequencies for an ensemble of random lasers in the two-mode regime was computed. The random lasers are implemented as open chaotic cavities filled with an active medium. The spectral…

Mesoscale and Nanoscale Physics · Physics 2007-10-29 Oleg Zaitsev

We report on a novel kind of transition in random lasers induced by the geometrical confinement of the emitting material. Different dye doped paper devices with controlled geometry are fabricated by soft-lithography and show two…

Optics · Physics 2015-06-22 N. Ghofraniha , I. Viola , A. Zacheo , V. Arima , G. Gigli , C. Conti

Here we experimentally map the dynamics of electron plasma waves in laser solid interaction. We do time resolved measurements of second harmonic and hard X-ray generation from interaction of intense ($10^{16} W cm^{-2}$, 100 fs, 800nm)…

Plasma Physics · Physics 2007-05-23 Arvinder S. Sandhu , G. Ravindra Kumar , S. Sengupta , A. Das , P. K. Kaw

Collective coherent scattering of laser light by an ensemble of polarizable point particles creates long range interactions, whose properties can be tailored by choice of injected laser powers, frequencies and polarizations. We use a…

Quantum Physics · Physics 2015-06-17 Stefan Ostermann , Matthias Sonnleitner , Helmut Ritsch

We present the first calculation of coherent backscattering with inelastic scattering by saturated atoms. We consider the scattering of a quasi-monochromatic laser pulse by two distant atoms in free space. By restricting ourselves to…

Quantum Physics · Physics 2009-11-10 T. Wellens , B. Gremaud , D. Delande , C. Miniatura

A new technique based on superposition of two speckle patterns is proposed and demonstrated for controlled modulation of the spatial polarization distribution of the resultant speckle. It is demonstrated both theoretically and…

Optics · Physics 2021-11-15 Abhijit Roy , Rakesh K. Singh , Maruthi M. Brundavanam

The spatial coherence of an atomic wavepacket can be detected in the scattered photons, even when the center-of-mass motion is in the quantum coherent superposition of two distant, non-overlapping wave packets. Spatial coherence manifests…

Biologically inspired photonic structures are the key for technological advances and for miniaturized lasers. Here random lasers in dye-doped titania with the disordered structure of paper are proposed. Sharp electromagnetic resonances with…

A laser is not necessarily a sophisticated device: Pumping energy into an amplifying medium randomly filled with scatterers, a powder for instance, makes a perfect "random laser." In such a laser, the absence of mirrors greatly simplifies…

Optics · Physics 2015-06-15 N. Bachelard , S. Gigan , X. Noblin , P. Sebbah

We experimentally study spatial fluctuations of the local density of states (LDOS) inside three-dimensional random photonic media. The LDOS is probed at many positions inside the random photonic media by measuring emission rates of a large…

Optics · Physics 2010-07-06 M. D. Birowosuto , S. E. Skipetrov , W. L. Vos , A. P. Mosk

Random lasing is an intriguing phenomenon occurring in disordered structures with optical gain. In such lasers, the scattering of light provides the necessary feedback for lasing action. Because of the light scattering, the random lasing…

Thomson scattering of laser light is one of the most fundamental diagnostics of plasma density, temperature and magnetic fields. It relies on the assumption that the properties in the probed volume are homogeneous and constant during the…

Plasma Physics · Physics 2016-04-29 P. M. Kozlowski , B. J. B. Crowley , D. O. Gericke , S. P. Regan , G. Gregori