Skip to main content Accessibility help
×
  1. Home
  2. Browse subjects
  3. Engineering
  4. Engineering: general interest
  5. Content listing

Refine search

Refine search

Access:
Content type:
Publication date:
Apply   From and To filters
Subject: Show more
Journals Show more
Publishers: Show more
Societies Show more
Series: Show more
Collections: Show more

Actions for selected content:

Select all | Deselect all
  • View selected items
  • Export citations
  • Download PDF (zip)
  • Save to Kindle
  • Save to Dropbox
  • Save to Google Drive

Save Search

You can save your searches here and later view and run them again in "My saved searches".

Please provide a title, maximum of 40 characters.
Cancel
×

9746 results in Engineering: general interest

Page 30 of 488

  • 11 - Atomic Physics Applied to the Solid State

  • from Part II - Applications of Atomic Physics
  • Mark Fox, University of Sheffield
  • Book:
    A Student's Guide to Atomic Physics
    Published online:
    21 June 2018
    Print publication:
    14 June 2018, pp 202-225

  • Summary

    Solids are made up of atoms bound together in crystals, and the understanding of their quantized states is a subject in its own right, namely solid-state physics. In this chapter, we briefly look to see how the general principles developed in atomic physics can be applied to solid-state systems. This will enable us to obtain a basic understanding of light emission in solids. The focus of the chapter will be restricted to two main examples of optically active solid-state materials:

  • (i) Semiconductors: Semiconductors lie at the heart of modern technology. The silicon chip underpins the electronics industry, while the optoelectronics industry exploits the optical properties of compound semiconductors such as GaAs. Our task here will be to apply simple principles of atomic physics to understand the electronic states of impurities in semiconductors, and the mechanisms of light emission and detection.

  • (ii) Ions doped into optical hosts: Here we consider materials such as ruby, where chromium is lightly doped into Al2O3, with the Cr3+ ions substituting for the Al3+ ions in the crystal. Pure Al2O3 is a colorless, transparent crystal, and the characteristic red color of ruby arises from transitions associated with the Cr3+ ions. Our task will be to understand how the transitions of the Cr3+ ions in the crystal relate to the atomic states of Cr3+ ions in isolation.

    • In both cases, it will not be possible to give a comprehensive treatment; the aim of the chapter is to explain a few basic principles that can lay the foundations for further study. This author has written another book in which these topics are explained in much greater depth. See Fox (2010).

    Solid-State Spectroscopy

    Chapter 3 developed the basic principles governing optical transitions in atoms. In this section, we shall see how these principles carry over to solid-state systems.

    Selection Rules

    The electric-dipole (E1) interaction is the strongest term in the light-matter Hamiltonian, as discussed in Section 3.3. The selection rules that follow from analysis of the E1 perturbation and the wave functions of atomic states were derived in Section 3.4, and are summarized in Table 3.1. These selection rules carry over directly to optical transitions in solid-state systems.

Strategic Management of Innovation and Design
  • Pascal Le Masson, Benoît Weil, Armand Hatchuel
  • Published online:
    28 May 2018
    Print publication:
    09 September 2010
  • There is now widespread agreement that innovation holds the key to future economic and social prosperity in developed countries. Experts studying contemporary capitalism also agree that the battle against unemployment and relocations can only be won through innovation. But what kind of innovation is required and what is the best way to manage, steer and organize it? Grounded on experiences of innovative firms and based on recent design theories, this book argues that instead of relying on traditional R&D and project management techniques, the strategic management of innovation must be based on innovative design activities. It analyses and explains new management principles and techniques that deal with these activities, including innovation fields, lineages, C-K (Concept-Knowledge) diagrams and design spaces. The book is ideal for advanced courses in innovation management in industrial design schools, business schools, engineering schools, as well as managers looking to improve their practice.

Page 30 of 488