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Stimulated Raman scattering is a well-known nonlinear process that can be harnessed to produce optical gain in a wide variety of media. This effect has been used to produce the first silicon-based lasers and high-gain amplifiers.…

Optics · Physics 2008-10-13 D. R. Solli , P. Koonath , B. Jalali

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

A theory of lasing in an optically thin layer of active centers disposed at a metal surface is developed from first principles. The approach is based on a rigorous account of the local field in a close vicinity of a reflective surface which…

Optics · Physics 2022-08-15 V. G. Bordo

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

A novel method is proposed to measure the refractive indices (RIs) of the materials of different transparent solid state media. To exploit the advantage of non-contact measurement laser beam interferometry is used as an effective technique…

Physics Education · Physics 2024-06-19 Arnab Pal , Kriti R. Sahu , Pradipta Panchadhyayee , Debapriyo Syam

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…

Recently, random lasing in complex networks has shown efficient lasing over more than 50 localised modes, promoted by multiple scattering over the underlying graph. If controlled, these network lasers can lead to fast-switching…

A disordered structure embedding an active gain material and able to lase is called random laser (RL). The RL spectrum may appear either like a set of sharp resonances or like a smooth line superimposed to the fluorescence. A recent letter…

Optics · Physics 2015-06-03 M. Leonetti , C. Conti , C. Lopez

A color-switchable random laser is designed through directly coupling random laser with a commercial optical fiber. By using a simple approach of selectively coating the random gain layer on the surface of fiber, the red and yellow random…

Optics · Physics 2019-10-07 Yaoxing Bian , Xiaoyu Shi , Mengnan Hu , Zhaona Wang

A model to simulate the phenomenon of random lasing is presented. It couples Maxwell's equations with the rate equations of electronic population in a disordered system. Finite difference time domain methods are used to obtain the field…

Disordered Systems and Neural Networks · Physics 2009-10-31 Xunya Jiang , C. M. Soukoulis

We present a numerical study of lasing modes in diffusive random media with local pumping. The reabsorption of emitted light suppresses the feedback from the unpumped part of the sample and effectively reduces the system size. The lasing…

Disordered Systems and Neural Networks · Physics 2016-08-31 A. Yamilov , X. Wu , H. Cao , A. L. Burin

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

A two-dimensional (2D) solid-state random laser emitting in the visible is demonstrated, in which optical feedback is provided by a controlled disordered arrangement of air-holes in a dye-doped polymer film. We find an optimal scatterer…

Optics · Physics 2023-05-30 Bhupesh Kumar , Ran Homri , Patrick Sebbah

We demonstrate lasing into counter-propagating modes of a ring cavity using a gas of cold atoms as a gain medium. The laser operates under the usual conditions of magneto-optical trapping with no additional fields. We characterize the…

Atomic Physics · Physics 2018-10-24 Balazs Megyeri , Graeme Harvie , Andreas Lampis , Jon Goldwin

A laser can be understood as thermodynamic engine converting heat to a coherent single mode field close to Carnot efficiency. From this perspective spectral shaping of the excitation light generates a higher effective temperature on the…

Quantum Physics · Physics 2013-05-30 K. Sandner , H. Ritsch

We describe a subluminal laser which is extremely stable against perturbations. It makes use of a composite gain spectrum consisting of a broad background along with a narrow peak. The stability of the laser, defined as the change in…

A recent paper showed how to construct a lens that focuses near field radiation and hence produce resolution unlimited by wavelength. The prescription requires lossless materials with negative refractive index: finite loss cuts off the…

Condensed Matter · Physics 2009-11-07 S. Anantha Ramakrishna , J. B. Pendry

Single-mode operation is a desirable but elusive property for lasers operating at high pump powers. Typically, single-mode lasing is attainable close to threshold, but increasing the pump power gives rise to multiple lasing peaks due to…

Optics · Physics 2022-08-02 B. F. Zhu , Q. Wang , D. Leykam , H. R. Xue , Q. J. Wang , Y. D. Chong

Active control of the pump spatial profile is proposed to exercise control over random laser emission. We demonstrate numerically the selection of any desired lasing mode from the emission spectrum. An iterative optimization method is…

Random lasers are unique systems where lasing occurs due to repetitive scattering in a disordered nanostructure. Previous descriptions of random lasing are numerous, however a full time-dependent theory that describes the introduction of…

Optics · Physics 2019-11-21 Zachariah Peterson