Fundamentals of Materials Science and Engineering: An Integrated Approach, 3e

GTBL042-19 GTBL042-Callister-v2 September 13, 2007 13:59

Revised Pages

Questions and Problems • 787

Optical Fibers in Communications

This chapter concluded with a discussion of the use of optical fibers in our modern

telecommunications. Using fiber-optic technology, transmission of information is

interference free, rapid, and intense.

IMPORTANT TERMS AND CONCEPTS

Absorption

Color

Electroluminescence

Excited state

Fluorescence

Ground state

Index of refraction

Laser

Light-emitting diode (LED)

Luminescence

Opaque

Phosphorescence

Photoconductivity

Photon

Planck’s constant

Reflection

Refraction

Translucent

Transmission

Transparent

REFERENCES

Javan, A., “The Optical Properties of Materials,”

Scientific American,Vol. 217, No. 3, September

1967, pp. 238–248.

Kingery, W. D., H. K. Bowen, and D. R. Uhlmann,

Introduction to Ceramics,2nd edition, Wiley,

New York, 1976, Chapter 13.

Ralls, K. M., T. H. Courtney, and J. Wulff,Intro-

duction to Materials Science and Engineering,

Wiley, New York, 1976, Chapter 27.

Rowell, J. M., “Photonic Materials,” Scientific

American, Vol. 255, No. 4, October 1986,

pp. 146–157.

QUESTIONS AND PROBLEMS

Additional problems and questions for this chapter may be found on both Student and

Instructor Companion Sites atwww.wiley.com/college/callister.

Electromagnetic Radiation

19.1Visible light having a wavelength of 5× 10 −^7

m appears green. Compute the frequency and

energy of a photon of this light.

Atomic and Electronic Interactions

19.2 (a)Briefly describe the phenomenon of elec-

tronic polarization by electromagnetic radia-

tion.(b)What are two consequences of elec-

tronic polarization in transparent materials?

Refraction

19.3In ionic materials, how does the size of the

component ions affect the extent of elec-

tronic polarization?

19.4Compute the velocity of light in diamond,

which has a dielectric constantrof 5.5 (at

frequencies within the visible range) and a

magnetic susceptibility of−2.17× 10 −^5.

19.5Using the data in Table 19.1, estimate the

dielectric constants for silica glass (fused

silica), soda–lime glass, polytetrafluoroethy-

lene, polyethylene, and polystyrene, and

compare these values with those cited in

Table 12.5. Briefly explain any discrepancies.

Reflection

19.6It is desired that the reflectivity of light at

normal incidence to the surface of a transpar-

ent medium be less than 5.0%. Which of the

following materials in Table 19.1 are likely

candidates: soda–lime glass, Pyrex glass, per-

iclase, spinel, polystyrene, and polypropy-

lene? Justify your selections.