Search results for "spontaneous emission"
showing 10 items of 145 documents
Optical gain, spontaneous and stimulated emission of surface plasmon polaritons in confined plasmonic waveguide
2010
International audience; We develop a theoretical model to compute the local density of states in a confined plasmonic waveguide. Based on this model, we derive a simple formula with a clear physical interpretation for the lifetime modification of emitters embedded in the waveguide. The gain distribution within the active medium is then computed following the formalism developed in a recent work [Phys. Rev. B 78, 161401 (2008)], by taking rigorously into account the pump irradiance and emitters lifetime modifications in the system. We finally apply this formalism to describe gain–assisted propagation in a dielectric–loaded surface plasmon polariton waveguide.
Optical Shielding of Destructive Chemical Reactions between Ultracold Ground-State NaRb Molecules
2020
Polar quantum gases represent promising platforms for studying many-body physics and strongly correlated systems with possible applications e.g. in quantum simulation or quantum computation. Due to their large permanent electric dipole moment polar molecules in electric field exhibit strong long-range anisotropic dipole-dipole interactions (DDIs). The creation and trapping of ultracold dipolar diatomic molecules of various species are feasible in many experimental groups nowadays. However long time trapping is still a challenge even in the case of the so called nonreactive molecules which are supposed to be immune against inelastic collisions in their absolute ground state [1] . Various hyp…
Multi-level optimization of a fiber transmission system via nonlinearity management
2006
Nonlinearity management is explored as a complete tool to obtain maximum transmission reach in a WDM fiber transmission system, making it possible to optimize multiple system parameters, including optimal dispersion pre-compensation, with fast simulations based on the continuous-wave approximation. © 2006 Optical Society of America.
Understanding Hawking Radiation from Simple Models of Atomic Bose-Einstein Condensates
2013
This chapter is an introduction to the Bogoliubov theory of dilute Bose condensates as applied to the study of the spontaneous emission of phonons in a stationary condensate flowing at supersonic speeds. This emission process is a condensed-matter analog of Hawking radiation from astrophysical black holes but is derived here from a microscopic quantum theory of the condensate without any use of the analogy with gravitational systems. To facilitate physical understanding of the basic concepts, a simple one-dimensional geometry with a stepwise homogenous flow is considered which allows for a fully analytical treatment.
Slow-light soliton dynamics with relaxation
2007
We solved the problem of soliton dynamics in the presence of relaxation. We demonstrate that the spontaneous emission of atoms is strongly suppressed due to nonlinearity. The spatial shape of the soliton is well preserved.
Exploring Quantum Matter with Ultracold Atoms in Optical Lattices
2005
Publisher Summary This chapter explores quantum matter with ultracold atoms in optical lattices. The chapter focuses on bosonic atoms in optical lattices and on the regime where strong correlations between the atoms become important. In the interaction of atoms with coherent light fields, two fundamental forces arise. The Doppler force is dissipative in nature and can be used to efficiently laser cool a gas of atoms and relies on the radiation pressure together with spontaneous emission. The dipole force creates a purely conservative potential in which the atoms can move. No cooling can be realized with this dipole force, however if the atoms are cold enough initially, they may be trapped i…
Radiative emission due to atomic self-dressing in QED
2002
We study the radiative emission due to the self-dressing of a two-level atom, initially in its bare ground state, interacting with the zero-point electromagnetic field. Evolution in time leads to the formation of a dressed ground state of lower energy. This energy difference between bare and dressed ground state is taken into account by the emission of real photons. In order to describe this aspect of the self-dressing process we study the transition probability amplitude from the initial bare state to an asymptotic state consisting of the atom in its dressed ground state plus some real photons. Adopting nonperturbative techniques based on the resolvent method we find that the bare-dressed …
Accurate tuning of mismatched twin-core fiber filters
1998
We have demonstrated a reproducible and accurate way of tuning the coupling wavelength of a mismatched twin-core filter. This method allows high quality all-fiber filters to be implemented with low loss at any desired wavelength over a range of few hundred nanometers from the same fiber. An ~500-nm tuning range is demonstrated, limited only by the measurement setup and not by the technique itself. Highly accurate control of the filtering wavelength in combination with control of filtering strength by adjustment of the length of the twin-core fibers allows complex filter profiles to be implemented by cascading of several different filters. These filters are also very stable to a change in te…
Purcell factor for 3D- dipolar emitter coupling to 2D- plasmonic waveguides
2011
We theoretically investigate spontaneous emission of a quantum (3D) dipolar emitter located near a (2D) plasmonic waveguide of arbitrary form. The channels into which emitter couples (plasmon, scattering, electron-hole pairs creation) are well identified.