{"title":"Comments about Dispersion of Light Waves","authors":"H. Lefèvre","doi":"10.1051/jeos/2022001","DOIUrl":null,"url":null,"abstract":". Dispersion of light waves is well known, but the subject deserves some comments. Certain classical equations do not fully respect causality; as an example, group velocity v g is usually given as the fi rst derivative of the angular frequency x with respect to the angular spatial frequency k m (or wavenumber) in the medium, whereas it is k m that depends on x . This paper also emphasizes the use of phase index n and group index n g , as inverse of their respective velocities, normalized to 1/ c , the inverse of free-space light velocity. This clari fi es the understanding of dispersion equations: group dispersion parameter D is related to the fi rst derivative of n g with respect to wavelength k , whilst group velocity dispersion GVD is also related to the fi rst derivative of n g , but now with respect to angular frequency x . One notices that the term second order dispersion does not have the same meaning with k , or with x . In addition, two original and amusing geometrical constructions are proposed; they simply derive group index n g from phase index n with a tangent , which helps to visualize their relationship. This applies to bulk materials, as well as to optical fi bers and waveguides, and this can be extended to birefringence and polarization mode dispersion in polarization-maintaining fi bers or birefringent waveguides.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":" ","pages":""},"PeriodicalIF":1.9000,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the European Optical Society-Rapid Publications","FirstCategoryId":"4","ListUrlMain":"https://doi.org/10.1051/jeos/2022001","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"OPTICS","Score":null,"Total":0}
引用次数: 2
Abstract
. Dispersion of light waves is well known, but the subject deserves some comments. Certain classical equations do not fully respect causality; as an example, group velocity v g is usually given as the fi rst derivative of the angular frequency x with respect to the angular spatial frequency k m (or wavenumber) in the medium, whereas it is k m that depends on x . This paper also emphasizes the use of phase index n and group index n g , as inverse of their respective velocities, normalized to 1/ c , the inverse of free-space light velocity. This clari fi es the understanding of dispersion equations: group dispersion parameter D is related to the fi rst derivative of n g with respect to wavelength k , whilst group velocity dispersion GVD is also related to the fi rst derivative of n g , but now with respect to angular frequency x . One notices that the term second order dispersion does not have the same meaning with k , or with x . In addition, two original and amusing geometrical constructions are proposed; they simply derive group index n g from phase index n with a tangent , which helps to visualize their relationship. This applies to bulk materials, as well as to optical fi bers and waveguides, and this can be extended to birefringence and polarization mode dispersion in polarization-maintaining fi bers or birefringent waveguides.
期刊介绍:
Rapid progress in optics and photonics has broadened its application enormously into many branches, including information and communication technology, security, sensing, bio- and medical sciences, healthcare and chemistry.
Recent achievements in other sciences have allowed continual discovery of new natural mysteries and formulation of challenging goals for optics that require further development of modern concepts and running fundamental research.
The Journal of the European Optical Society – Rapid Publications (JEOS:RP) aims to tackle all of the aforementioned points in the form of prompt, scientific, high-quality communications that report on the latest findings. It presents emerging technologies and outlining strategic goals in optics and photonics.
The journal covers both fundamental and applied topics, including but not limited to:
Classical and quantum optics
Light/matter interaction
Optical communication
Micro- and nanooptics
Nonlinear optical phenomena
Optical materials
Optical metrology
Optical spectroscopy
Colour research
Nano and metamaterials
Modern photonics technology
Optical engineering, design and instrumentation
Optical applications in bio-physics and medicine
Interdisciplinary fields using photonics, such as in energy, climate change and cultural heritage
The journal aims to provide readers with recent and important achievements in optics/photonics and, as its name suggests, it strives for the shortest possible publication time.