Colour and the Optical Properties of Materials

Richard J. D. Tilley

• Publisher: Wiley
• Year: 2019
• ISBN:
  9781119554684
• Edition: 3
• Topic: Technology & Engineering
• Subtopic: Civil Engineering
• Index: Technology & Engineering

The updated third edition of the only textbook on colour

The revised third edition of Colour and the Optical Properties of Materials focuses on the ways that colour is produced, both in the natural world and in a wide range of applications. The expert author offers an introduction to the science underlying colour and optics and explores many of the most recent applications. The text is divided into three main sections: behaviour of light in homogeneous media, which can largely be explained by classical wave optics; the way in which light interacts with atoms or molecules, which must be explained mainly in terms of photons; and the interaction of light with insulators, semiconductors and metals, in which the band structure notions are of primary concern.

The updated third edition retains the proven concepts outlined in the previous editions and contains information on the significant developments in the field with many figures redrawn and new material added. The text contains new or extended sections on photonic crystals, holograms, flat lenses, super-resolution optical microscopy and modern display technologies. This important book:

• Offers and introduction to the science that underlies the everyday concept of colour
• Reviews the cross disciplinary subjects of physics, chemistry, biology and materials science, to link light, colour and perception
• Includes information on many modern applications, such as the numerous different colour displays now available, optical amplifiers lasers, super-resolution optical microscopy and lighting including LEDs and OLEDs
• Contains new sections on photonic crystals, holograms, flat lenses, super-resolution optical microscopy and display technologies
• Presents many worked examples, with problems and exercises at the end of each chapter

Written for students in materials science, physics, chemistry and the biological sciences, the third edition of Colour and The Optical Properties of Materials covers the basic science of the topic and has been thoroughly updated to include recent advances in the field.

1
Light and Colour

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• What is colour?
• Why do hot objects become red or white hot?
• How does laser light differ from light from the sun?

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Colour may be considered to be the subjective appearance of light as detected by the eye. Broadly speaking, light leaves the generating source, possibly interacts with matter in the course of passage, and then enters the eye. This book is principally about this interaction of light and materials and how it influences our perception of the colour of the light so produced. This perception of colour, the result of an eye–brain combination, is summarised by the term vision. Essentially, vision forms a subject area outside of the central area of interest here. However, it should not be totally neglected, and in this introductory chapter, is briefly described.

The chapter is divided into three sections: the first describes the relationship between light and colour (Sections 1.1–1.4); the second concerns light production (Sections 1.5–1.8), while vision and colour perception end the chapter (Sections 1.9–1.13).

1.1 Light and Colour

1.1.1 Light rays

In elementary optics, light can usefully be considered to consist of light rays. These can be thought of as extremely fine beams that travel in a series of straight lines from the light source and thence, ultimately, to the eye. The majority of simple optical instruments can be constructed within the framework of this idea. However, the ray concept breaks down when the behaviour of light is critically tested, and the performance of optical instruments, as apart from their construction, cannot be explained in terms of light rays. Moreover, colour is not conveniently defined in this way. For this, more complex ideas are needed.

1.1.2 Light waves

Early theories concerning the nature of light were divided over whether it was composed of small particles (or corpuscles) or whether it was made up of waves. Newton, in his book Optics (1704), endorsed the particle concept, which was supported on philosophical grounds by Descartes. On the other hand, Huygens, a contemporary, thought that light was wavelike, a point of view also supported by Hooke. Young provided strong evidence for the wave theory of light by demonstrating the interference of light beams passing through two adjacent slits (1803). Shortly afterwards, Fresnell and Arago explained the polarisation of light in terms of transverse light waves. However, none of these explanations was able to completely refute the particle hypothesis. Nevertheless, the wave versus particle theories differed in one fundamental aspect that could be tested. When light enters water it is refracted, that is, the trajectory of the light appears to alter. In terms of corpuscles, this implied a speeding up of the light in water relative to air. The wave theory demanded that the light should move more slowly in water than air. The experiments were complicated by the enormous speed of light, which was known to be about 3 × 10⁸ m s⁻¹, and it was not until April 1850 that Foucault first proved that light moved slower in water than air, and seemingly killed the corpuscular theory then and there. Confirmation of the result by Fizeau a few weeks later removed all doubt.

Over the years, the wave theory became entrenched and reached its peak when Maxwell published his theory of electromagnetic radiation in 1865, which showed that light behaved as an electromagnetic wave, with both electric and magnetic components. [Maxwell's (original) equations that describe electromagnetic waves are fairly indigestible. The compact form now universally known as Maxwell's equations was, in fact, formulated by O. Heaviside, some years later.] Maxwell's theory, which implied the existence of an extensive electromagnetic wave spectrum was confirmed experimentally by Hertz in 1888, whose experiments led to the production and detection of a...