Book contents
- Frontmatter
- Contents
- Preface
- Acknowledgements
- 1 Historical introduction
- 2 A review of some basic concepts
- 3 The polarization properties of quasi-monochromatic light
- 4 Linear optical systems acting on polarized light
- 5 Solar polarimetry
- 6 Absorption and dispersion
- 7 The radiative transfer equation
- 8 The RTE in the presence of a magnetic field
- 9 Solving the radiative transfer equation
- 10 Stokes spectrum diagnostics
- 11 Inversion of the RTE
- Index
6 - Absorption and dispersion
Published online by Cambridge University Press: 11 August 2009
- Frontmatter
- Contents
- Preface
- Acknowledgements
- 1 Historical introduction
- 2 A review of some basic concepts
- 3 The polarization properties of quasi-monochromatic light
- 4 Linear optical systems acting on polarized light
- 5 Solar polarimetry
- 6 Absorption and dispersion
- 7 The radiative transfer equation
- 8 The RTE in the presence of a magnetic field
- 9 Solving the radiative transfer equation
- 10 Stokes spectrum diagnostics
- 11 Inversion of the RTE
- Index
Summary
“El clero era absorbente”. Sobre todo Don Fermín había sido un poco jesuita.
—Leopoldo Alas, Clarín, 1885.‘The clergy were like a sponge.’ And what was more, Don Fermin had once been something of a Jesuit.
So far we have avoided detailed discussion about two physical phenomena that are crucial in the context of this book and for any understanding of the interaction between matter and radiation in general. These two phenomena are absorption and dispersion, that is, the removal of energy from the electromagnetic field by matter and the dephasing of the electric field components as light streams through the medium. Although we have barely mentioned the existence of these effects, we shall need a deeper insight into both of them. We shall see that retardance, birefringence, and absorption properties of polarization systems, assumed in the preceding sections, are based on these phenomena, whose wavelength dependence is understood in terms of the wavelength dependence of the dielectric permittivity and, hence, of the refractive index of the medium. By studying absorption and dispersion we are producing the necessary bricks with which to build a theory of radiative energy transfer which will be discussed in following chapters. We shall continue to assume unit isotropic magnetic permeability of μ = 1 for the medium.
Certainly, a full account of absorption and dispersion processes can be carried out only within the framework of quantum mechanics.
- Type
- Chapter
- Information
- Introduction to Spectropolarimetry , pp. 87 - 101Publisher: Cambridge University PressPrint publication year: 2003