文档介绍：Source: Photonics Essentials
Part
I
Introductory Concepts
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Introductory Concepts
Downloaded from Digital Engineering Library @ McGraw-Hill ()
Copyright © 2004 The McGraw-panies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.
Source: Photonics Essentials
Chapter
1
Introduction
Photons have been around ever since the Big Bang, which is a long
time. Photons, by definition, are always on the move: 3 × 1010 cm/sec
in air. Some of the important milestones in the history of the human
civilization are those at which we have improved our ability to control
the movement of photons. A few notable examples are the control of
fire, the design of lenses, the conception of Maxwell’s equations, the
invention of photography, broadcast radio, and the laser.
Photonics is the study of how photons and electronics interact, how
electrical current can be used to create photons as in a semiconductor
laser diode, and how photons can create an electrical current, as in a
solar cell. The field of photonics is in its infancy. Great discoveries re-
main to be made in using photonics to improve our lives.
The list of applications in photonics is long. Some of the rapidly
growing areas are:
Ecology:
Solar cell energy generation
Air quality and pollution monitoring
Imaging:
Camcorders
Satellite weather pictures
Digital cameras
Night vision
Military surveillance
3
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Introduction
4 Introductory Concepts
Information displays:
Computer terminals
Traffic signals
Operating displays in automobiles and appliances
Information