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Bloch equations for the atomic population and the polarization/coherence and the equation of motion for the photon number in a laser are solved in steady state as a function of the pump rate. Two level atom and two modes of three levels…

Quantum Physics · Physics 2007-05-23 Gennady A. Koganov , Reuben Shuker

We propose a PDE-controllability based approach to the enhancement of diffusive mixing for passive scalar fields. Unlike in the existing literature, our relaxation enhancing fields are not prescribed $\textit{ab initio}$ at every time and…

Analysis of PDEs · Mathematics 2025-06-30 Kai Koike , Vahagn Nersesyan , Manuel Rissel , Marius Tucsnak

Among the various attempts to understand collisionless absorption of intense ultrashort laser pulses a variety of models has been invented to describe the laser beam target interaction. In terms of basic physics collisionless absorption is…

Plasma Physics · Physics 2015-03-16 T. Liseykina , P. Mulser , M. Murakami

We find a general class of nontrivial stationary states in inelastic gases where, due to dissipation, energy is transfered from large velocity scales to small velocity scales. These steady-states exist for arbitrary collision rules and…

Soft Condensed Matter · Physics 2007-05-23 E. Ben-Naim , J. Machta

We present a new theoretical approach for collisional absorption of laser energy in dense plasmas which accommodates arbitrary frequencies and high intensities of the laser field. We establish a connection between laser absorption by…

Plasma Physics · Physics 2015-05-13 A. Grinenko , D. O. Gericke

Using a three dimensional relativistic particle-in-cell code we have performed numerical experiments of plasma shells colliding at relativistic velocities. Such scenarios are found in many astrophysical objects e.g. the relativistic outflow…

Astrophysics · Physics 2007-05-23 C. B. Hededal , J. Trier Frederiksen , T. Haugboelle , Å. Nordlund

We consider self-pulsing in lasers with a gain section and an absorber section via a mechanism known as Q-switching, as described mathematically by the Yamada ordinary differential equation model for the gain, the absorber and the laser…

Dynamical Systems · Mathematics 2020-12-30 Robert Otupiri , Bernd Krauskopf , Neil G. R. Broderick

Laser-plasma instability (LPI) is one of the main obstacles in laser-driven inertial confinement fusion (ICF) for achieving predictable and reproducible fusion at high gain. For the first time we have proved analytically and confirmed with…

Plasma Physics · Physics 2022-11-24 Yi Guo , Xiaomei Zhang , Dirui Xu , Xinju Guo , Baifei Shen , Ke Lan

We explore energy transfer in a generic three-level system, which is coupled to three non-equilibrium baths. Built on the concept of quantum heat engine, our three-level model describes non-equilibrium quantum processes including…

Quantum Physics · Physics 2016-02-17 Dazhi Xu , Chen Wang , Yang Zhao , Jianshu Cao

Laser powered dielectric structures achieve high-gradient particle acceleration by taking advantage of modern laser technology capable of producing electric fields in excess of 10GV/m. These fields can drive the bulk dielectric beyond its…

In standard lasers, light amplification requires population inversion between an upper and a lower state to break the reciprocity between absorption and stimulated emission. However, in a medium prepared in a specific superposition state,…

We study the decoherence of a system of $N$ non-interacting heavy particles (atoms) due to coherent scattering with a background gas. We introduce a framework for computing the induced phase shift and loss of contrast for arbitrary…

Quantum Physics · Physics 2024-09-11 Leonardo Badurina , Clara Murgui , Ryan Plestid

We study the excitation of a two-level system (2LS) by quantum light, thereby bringing our previous studies~(see part~I. of this series) to a target that is quantum itself. While there is no gain for the quantum state of the target as…

Quantum Physics · Physics 2017-02-15 J. C. López Carreño , C. Sánchez Muñoz , E. del Valle , F. P. Laussy

Sustained collisionless interpenetrating plasma flows have been generated on the OMEGA laser facility to enable direct investigation of nonlinear evolution of fields generated by electromagnetic kinetic instabilities. FLASH simulations and…

A transverse mode selective laser system with gain regulation by a digital micromirror device (DMD) is presented in this letter. The gain regulation in laser medium is adjusted by the switch of the patterns loaded on DMD. Structured pump…

Optics · Physics 2021-08-10 Zilong Zhang , Yuan Gao , Xin Wang , Suyi Zhao , Yuchen Jie , Changming Zhao

Stimulated emission (SE) was measured from two InGaN multiple quantum well (MQW) laser structures with different In compositions. SE threshold power densities (I_th) increased with increasing QW depth (x). Time-resolved differential…

Mesoscale and Nanoscale Physics · Physics 2015-06-24 Umit Ozgur , Henry O. Everitt , Stacia Keller , Steven P. DenBaars

We investigate the dispersion and the absorption properties of a weak probe field in a three-level pump-probe atomic system. It is shown that the slope of dispersion changes from positive to negative just with the intensity of the coherent…

Quantum Physics · Physics 2010-01-20 M. Mahmoudi , S. Worya Rabiei , L. Ebrahimi Zohravi , M. Sahrai

Coherent manipulation of quasi-particles is a crucial method to realize ultrafast switching of the relating macroscopic order. In this letter, we studied coherent phonon generation under strong light field which allows to induce…

Optics · Physics 2020-03-11 Kento Uchida , Kohei Nagai , Naotaka Yoshikawa , Koichiro Tanaka

In this work, we review several results on development and application of incoherent version of GRAPE (Gradient Ascent Pulse Engineering) approach, inGRAPE, to optimization for open quantum systems driven by both coherent and incoherent…

Quantum Physics · Physics 2024-03-28 Vadim Petruhanov , Alexander Pechen

We study a very general four dimensional Field Theory model describing the dynamics of a massless higher spin $N$ symmetric tensor field particle interacting with a geometrical background.This model is invariant under the action of an…

High Energy Physics - Theory · Physics 2015-06-11 Giuseppe Bandelloni
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