Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1006.1700

Nonstationary electromagnetics of controllably dispersive media

Douglas H. Bradshaw, Michael D. Di Rosa

Published Jun 9, 2010• 0 citations
arXivHTMLPDF

Abstract

Recent experiments have demonstrated that it is possible to alter the dispersion of a medium without significantly altering its absorption or refractive index and that this may be done while a wave propagates through the medium. This possibility opens up a new set of potential experiments to the field of nonstationary optics. We consider the basic kinetics of waves propagating through a medium whose group and phase velocities are a function of position and time. We compare the dynamics of waves propagating through two homogeneous media, one a nondispersive medium with a time dependent phase velocity, and one a dispersive medium with a time dependent group velocity and show that new dynamic effects accompany new kinetic ones.

DOI
10.48550/arxiv.1006.1700

Related papers

From refractive index to stopped light

Jarosław Zaremba

Investigations of controlled modifications of dispersive properties of atomic media and of propagation of short laser pulses have recently become a dynamically developing field of theoretical and experimental researches. In this lecture a brief overview is presented of basic physical phenomena underlying modifications of a group velocity of a pulse propagating in an optically modified medium. In particular, the possibilities of slowing down this velocity to zero and of retrieving the stopped pulse are discussed.

ICTON Mediterranean Winter Conference (ICTON-MW)•Dec 1, 2009•0 citations

Dispersion, Controlled Dispersion, and Three Applications

Douglas H. Bradshaw

Over the past 15 years, several groups have engineered media that are both strongly dispersive and roughly transparent for some finite bandwidth. Relationships and intuitive models that are satisfactory when it is reasonable to neglect dispersion may then fail. We analyze three such cases of failure. First, a simple generalization of the Abraham and Minkowski momenta to dispersive media entails multiplying each per-photon momentum by $n/n_g$, where $n$ is the refractive index and $n_g$ is the group index. The resulting forms are experimentally relevant for the case of the Abraham momentum, but not for the Minkowski momentum. We show how dispersion modulates the displacement of a sphere embedded in a dispersive medium by a pulse. Second, pulse transformation in a nonstationary medium is modulated by the presence of dispersion. Using an explicit description of the kinetics of dispersive nonstationary inhomogeneous media, we show how the group velocity can modulate pulse response to a change in the refractive index and how Doppler shifts may become large in a dispersive medium as the velocity of the Doppler shifting surface approaches the group velocity. We explain a simple way to use existing technology to either compress or decompress a given pulse, changing its bandwidth and spatial extent by several orders of magnitude while otherwise preserving its envelope shape. Finally, we note that the nature of a single optical cavity quasimode depends on intracavity dispersion. We show that the quantum field noise associated with a single cavity mode may be modulated by dispersion. For a well-chosen mode in a high-Q cavity, this can amount to either an increase or a decrease in total vacuum field energy by several orders of magnitude. We focus on the "white light cavity," showing that the quantum noise of an ideal white light cavity diverges as the cavity finesse improves.

arXiv:1005.5467•May 29, 2010•0 citations

Towards nonreciprocal pulse dynamics in a time-varying medium

Piyali Biswas, Somnath Ghosh

Abstract We demonstrate the nonreciprocal propagation of optical pulses in a linear dispersive medium with a time-varying refractive index. The change of refractive index with time breaks the time-translation symmetry of the spatially homogeneous medium compelling it to be inherently nonreciprocal. A time-reversal asymmetric field ratio of the counter-propagating optical pulses along with a frequency shift leading to spectral nonreciprocity in such dynamic media have been observed. The findings have emerged a new avenue to realize nonreciprocal light flow in dynamically tuned integration-feasible photonic systems.

Physica Scripta•Feb 1, 2023•2 citations

Fast Light, Slow Light and Left-Handed Light

Peter W. Milonni

The propagation of light in dispersive media is a subject of fundamental as well as practical importance. In recent years attention has focused in particular on how refractive index can vary with frequency in such a way that the group velocities of optical pulses can be much greater or much smaller than the speed of light in vacuum, or in which the refractive index can be negative. Treating these topics at an introductory to intermediate level, Fast Light, Slow Light and Left-Handed Light focuses on the basic theory and describes the significant experimental progress made during the past decade. The book pays considerable attention to the fact that superluminal group velocities are not in conflict with special relativity and to the role of quantum effects in preventing superluminal communication and violations of Einstein causality. It also explores some of the basic physics at the opposite extreme of very slow group velocities as well as stopped and regenerated light, including the concepts of electromagnetically induced transparency and dark-state polaritons. Another very active aspect of the subject discussed concerns the possibility of designing metamaterials in which the refractive index can be negative and propagating light is left-handed in the sense that the phase and group velocities are in opposite directions. The last two chapters are an introduction to some of the basic theory and consequences of negative refractive index, with emphasis on the seminal work carried out since 2000. The possibility that "perfect" lenses can be made from negative-index metamaterials-which has been perhaps the most controversial aspect of the field-is introduced and discussed in some detail.

Series in optics and optoelectronics•Nov 30, 2004•149 citations

Fast light, slow light and left-handed light

The propagation of light in dispersive media is a subject of fundamental as well as practical importance. In recent years attention has focused in particular on how refractive index can vary with frequency in such a way that the group velocities of optical pulses can be much greater or much smaller than the speed of light in vacuum, or in which the refractive index can be negative. Treating these topics at an introductory to intermediate level, Fast Light, Slow Light and Left-Handed Light focuses on the basic theory and describes the significant experimental progress made during the past decade. The book pays considerable attention to the fact that superluminal group velocities are not in conflict with special relativity and to the role of quantum effects in preventing superluminal communication and violations of Einstein causality. It also explores some of the basic physics at the opposite extreme of very slow group velocities as well as stopped and regenerated light, including the concepts of electromagnetically induced transparency and dark-state polaritons. Another very active aspect of the subject discussed concerns the possibility of designing metamaterials in which the refractive index can be negative and propagating light is left-handed in the sense that the phase and group velocities are in opposite directions. The last two chapters are an introduction to some of the basic theory and consequences of negative refractive index, with emphasis on the seminal work carried out since 2000. The possibility that "perfect" lenses can be made from negative-index metamaterials-which has been perhaps the most controversial aspect of the field-is introduced and discussed in some detail.

Materials Today•Feb 21, 2005•128 citations

Coherence properties of one-dimensional pulses in dispersive media

Weijian Wang, E. Wolf

In recent years longitudinal coherence of electron and neutron wave packets has been investigated,1,2 and it was shown that their coherence length remains unchanged even though the length of the wave packet increases on propagation.3,4 As pointed out in Ref. 3, one may expect that a similar result will hold for light that propagates in a dispersive medium. We present some new general theorems relating to an ensemble of identical 1-D optical pulses which propagate in a linear homogeneous medium of any given dispersive properties. In particular we derive a general expression for the mutual coherence function and for the cross-spectral density function of the pulse field in the medium in terms of the Fourier spectrum of a single pulse shape. The analysis brings out clearly the distinction (already noted in Ref. 4) between the coherence length and the coherence time of fields in dispersive media. We also show that the pulse field is spatially completely coherent at each frequency, even though the shape of each pulse changes on propagation. The results have potential application to interferometry with optical pulses and with de Broglie wave packets of elementary particles.

Annual Meeting Optical Society of America•Jan 1, 1988•0 citations
Recent experiments have demonstrated that it is possible to alter the dispersion of a medium without significantly altering its absorption or refractive index and that this may be done while a wave propagates through the medium. This possibility opens up a new set of potential experiments to the field of nonstationary optics. We consider the basic kinetics of waves propagating through a medium whose group and phase velocities are a function of position and time. We compare the dynamics of waves propagating through two homogeneous media, one a nondispersive medium with a time dependent phase velocity, and one a dispersive medium with a time dependent group velocity and show that new dynamic effects accompany new kinetic ones.
Investigations of controlled modifications of dispersive properties of atomic media and of propagation of short laser pulses have recently become a dynamically developing field of theoretical and experimental researches. In this lecture a brief overview is presented of basic physical phenomena underlying modifications of a group velocity of a pulse propagating in an optically modified medium. In particular, the possibilities of slowing down this velocity to zero and of retrieving the stopped pulse are discussed.
Over the past 15 years, several groups have engineered media that are both strongly dispersive and roughly transparent for some finite bandwidth. Relationships and intuitive models that are satisfactory when it is reasonable to neglect dispersion may then fail. We analyze three such cases of failure. First, a simple generalization of the Abraham and Minkowski momenta to dispersive media entails multiplying each per-photon momentum by n/ngn/n_gn/ng​, where nnn is the refractive index and ngn_gng​ is the group index. The resulting forms are experimentally relevant for the case of the Abraham momentum, but not for the Minkowski momentum. We show how dispersion modulates the displacement of a sphere embedded in a dispersive medium by a pulse. Second, pulse transformation in a nonstationary medium is modulated by the presence of dispersion. Using an explicit description of the kinetics of dispersive nonstationary inhomogeneous media, we show how the group velocity can modulate pulse response to a change in the refractive index and how Doppler shifts may become large in a dispersive medium as the velocity of the Doppler shifting surface approaches the group velocity. We explain a simple way to use existing technology to either compress or decompress a given pulse, changing its bandwidth and spatial extent by several orders of magnitude while otherwise preserving its envelope shape. Finally, we note that the nature of a single optical cavity quasimode depends on intracavity dispersion. We show that the quantum field noise associated with a single cavity mode may be modulated by dispersion. For a well-chosen mode in a high-Q cavity, this can amount to either an increase or a decrease in total vacuum field energy by several orders of magnitude. We focus on the "white light cavity," showing that the quantum noise of an ideal white light cavity diverges as the cavity finesse improves.
Abstract We demonstrate the nonreciprocal propagation of optical pulses in a linear dispersive medium with a time-varying refractive index. The change of refractive index with time breaks the time-translation symmetry of the spatially homogeneous medium compelling it to be inherently nonreciprocal. A time-reversal asymmetric field ratio of the counter-propagating optical pulses along with a frequency shift leading to spectral nonreciprocity in such dynamic media have been observed. The findings have emerged a new avenue to realize nonreciprocal light flow in dynamically tuned integration-feasible photonic systems.
The propagation of light in dispersive media is a subject of fundamental as well as practical importance. In recent years attention has focused in particular on how refractive index can vary with frequency in such a way that the group velocities of optical pulses can be much greater or much smaller than the speed of light in vacuum, or in which the refractive index can be negative. Treating these topics at an introductory to intermediate level, Fast Light, Slow Light and Left-Handed Light focuses on the basic theory and describes the significant experimental progress made during the past decade. The book pays considerable attention to the fact that superluminal group velocities are not in conflict with special relativity and to the role of quantum effects in preventing superluminal communication and violations of Einstein causality. It also explores some of the basic physics at the opposite extreme of very slow group velocities as well as stopped and regenerated light, including the concepts of electromagnetically induced transparency and dark-state polaritons. Another very active aspect of the subject discussed concerns the possibility of designing metamaterials in which the refractive index can be negative and propagating light is left-handed in the sense that the phase and group velocities are in opposite directions. The last two chapters are an introduction to some of the basic theory and consequences of negative refractive index, with emphasis on the seminal work carried out since 2000. The possibility that "perfect" lenses can be made from negative-index metamaterials-which has been perhaps the most controversial aspect of the field-is introduced and discussed in some detail.
The propagation of light in dispersive media is a subject of fundamental as well as practical importance. In recent years attention has focused in particular on how refractive index can vary with frequency in such a way that the group velocities of optical pulses can be much greater or much smaller than the speed of light in vacuum, or in which the refractive index can be negative. Treating these topics at an introductory to intermediate level, Fast Light, Slow Light and Left-Handed Light focuses on the basic theory and describes the significant experimental progress made during the past decade. The book pays considerable attention to the fact that superluminal group velocities are not in conflict with special relativity and to the role of quantum effects in preventing superluminal communication and violations of Einstein causality. It also explores some of the basic physics at the opposite extreme of very slow group velocities as well as stopped and regenerated light, including the concepts of electromagnetically induced transparency and dark-state polaritons. Another very active aspect of the subject discussed concerns the possibility of designing metamaterials in which the refractive index can be negative and propagating light is left-handed in the sense that the phase and group velocities are in opposite directions. The last two chapters are an introduction to some of the basic theory and consequences of negative refractive index, with emphasis on the seminal work carried out since 2000. The possibility that "perfect" lenses can be made from negative-index metamaterials-which has been perhaps the most controversial aspect of the field-is introduced and discussed in some detail.
In recent years longitudinal coherence of electron and neutron wave packets has been investigated,1,2 and it was shown that their coherence length remains unchanged even though the length of the wave packet increases on propagation.3,4 As pointed out in Ref. 3, one may expect that a similar result will hold for light that propagates in a dispersive medium. We present some new general theorems relating to an ensemble of identical 1-D optical pulses which propagate in a linear homogeneous medium of any given dispersive properties. In particular we derive a general expression for the mutual coherence function and for the cross-spectral density function of the pulse field in the medium in terms of the Fourier spectrum of a single pulse shape. The analysis brings out clearly the distinction (already noted in Ref. 4) between the coherence length and the coherence time of fields in dispersive media. We also show that the pulse field is spatially completely coherent at each frequency, even though the shape of each pulse changes on propagation. The results have potential application to interferometry with optical pulses and with de Broglie wave packets of elementary particles.