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Doppler broadening
About: Doppler broadening is a research topic. Over the lifetime, 5509 publications have been published within this topic receiving 92552 citations.
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TL;DR: In this article, the Anderson localization of a matter wave packet in a one-dimensional disordered potential was theoretically studied and an analytical model which included the initial phase-space density of the matter wave and the spectral broadening induced by the disorder was developed.
Abstract: We theoretically study the Anderson localization of a matter wave packet in a one-dimensional disordered potential. We develop an analytical model which includes the initial phase-space density of the matter wave and the spectral broadening induced by the disorder. Our approach predicts a behavior of the localized density profile significantly more complex than a simple exponential decay. These results are confirmed by large-scale and long-time numerical calculations. They shed new light on recent experiments with ultracold atoms and may impact their analysis.
44 citations
TL;DR: In this article, the authors studied the effect of the free carriers generated during the propagation of optical pulses, through the process of two-photon absorption, on the amplitude and phase of the optical pulses and determined the nature and extent of the generated spectral continuum.
Abstract: Spectral broadening in silicon through self-phase modulation is studied numerically and experimentally in the normal dispersion regime. Temporal dynamics of the free carriers generated during the propagation of optical pulses, through the process of two-photon absorption, affect the amplitude and phase of the optical pulses, thereby determining the nature and extent of the generated spectral continuum. Experimental results are obtained by propagating picosecond optical pulses in a silicon waveguide for intensities that span two orders of magnitude (1–150GW∕cm2). These results validate the conclusions drawn from numerical simulations that the continuum generation has a self-limiting nature in silicon.
43 citations
TL;DR: In this article, the average velocity-dependent electric dipole moment of an atomic radiator in a perturber gas was derived for the impact limit, combining Doppler and collision broadening, and it has the same structure in the case of a classical or a quantum-mechanical description.
Abstract: A kinetic equation is derived for the average velocity-dependent electric dipole moment of an atomic radiator in a perturber gas. This equation determines the spectral-line profile in the impact limit, combining Doppler and collision broadening, and it has the same structure in the case of a classical or a quantum-mechanical description. The kinetic equation is solved in several limiting cases, which generalize previous work. Quantities determining the profile are generalized complex loss factors, source factors and friction constants, which are expressed in terms of the exact quantum-mechanical scattering amplitudes. It is found that state-selecting collisions increase the collisional width, and decrease Dicke narrowing of the Doppler width. This type of collision is not properly accounted for in a classical theory.
43 citations
TL;DR: In this article, the authors investigated the spectral broadening of diode lasers in an external linear cavity with frequency-shifted feedback, and they observed a feedback level dependent frequency shift and continuous line broadening up to 5 GHz.
43 citations
TL;DR: In this paper, the longitudinal mode spectrum of stripe geometry double heterostructure (DH) lasers exhibits a spectral broadening of ∼ 0.8 A when the laser emits pulsations, which is due to an increase of the refractive index resulting from the reduction in the carrier concentration during the pulse.
Abstract: The longitudinal mode spectrum of stripe geometry double heterostructure (DH) lasers exhibits a spectral broadening of ∼ 0.8 A when the laser emits pulsations. The broadening results from a chirp to longer wavelengths which occurs during the ∼ 0.4 ns long pulse. The chirp is due to an increase of the refractive index resulting from the reduction in the carrier concentration during the pulse. Both plasma and band to band interactions affect the index change with the latter mechanism giving the dominant contribution. A comparison of the wavelength shift obtained during the pulse with the current dependent shift of the longitudinal modes at currents well below threshold confirms that the change in carrier concentration is responsible for the chirp.
43 citations