Skip to main content Accessibility help

We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.

Close cookie message
×
Hostname: page-component-66644f4456-2xp4c Total loading time: 0 Render date: 2025-02-12T18:20:03.327Z Has data issue: true hasContentIssue false

1 - Electromagnetic waves, light, and lasers

Published online by Cambridge University Press:  05 June 2014

Christopher C. Davis
Christopher C. Davis
Affiliation:
University of Maryland, College Park
Get access

Summary

The laser

A laser is an oscillator that operates at optical frequencies. These frequencies of operation lie within a spectral region that extends from the very far infrared to the vacuumultraviolet (VUV) or soft-X-ray region. At the lowest frequencies at which they operate, lasers overlap with the frequency coverage of masers, to which they are closely related, and millimeter-wave sources using solid-state or vacuum-tube electronics, such as TRAPATT, IMPATT, and Gunn diodes, klystrons, gyroklystrons, and traveling-wave tube oscillators, whose principles of operation are quite different [1]. In common with electronic-circuit oscillators, a laser is constructed using an amplifier with an appropriate amount of positive feedback. The positive feedback is generally provided by mirrors that re-direct light back and forth through the laser amplifier. The acronym LASER, which stands for light amplification by stimulated emission of radiation, is in reality therefore a slight misnomer.

A little bit of history

The basic physics underlying light emission and absorption by atoms and molecules was first expounded by Albert Einstein (1879–1955) in 1917 [2]. Richard Chace Tolman (1881–1948) observed that stimulated emission could lead to “negative absorption.” In 1928 Rudolph Walther Landenburg (1889–1953) confirmed the existence of stimulated emission and negative absorption. It is interesting to note that a famous spectroscopist, Curtis J. Humphreys (1898–1986), who for most of his career worked at the U.S. Naval Ordnance Laboratory in Corona, California, might have operated the first gas laser without knowing it.

Type
Chapter
Information
Lasers and Electro-optics
Fundamentals and Engineering
 , pp. 1 - 32
Publisher: Cambridge University Press
Print publication year: 2014

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

W. T., Silfvast, Laser Fundamentals, 2nd edn., Cambridge: Cambridge University Press, 2004.Google Scholar
O., Svelto, Principles of Lasers, 5th edn., New York: Springer, 2010.Google Scholar
A. E., Siegman, Lasers, Mill Valley, CA: University Science Books, 1985.Google Scholar
P. W., Milonni and J. H., Eberly, Lasers, 2nd edn., New York: Wiley, 2010.Google Scholar
A., Yariv, Optical Electronics in Modern Communications, 5th edn., Oxford: Oxford University Press, 1997.Google Scholar
A., Yariv, Quantum Electronics, 3rd edn., New York: Wiley, 1989.Google Scholar
[1] S. Y., Liao, Microwave Solid-State Devices, Englewood Cliffs, NJ: Prentice-Hall, 1985.Google Scholar
[2] A., Einstein, “Zur Quantentheorie der Strahlung,” Phys. Z. 18, 121–128, 1917.Google Scholar
[3] C. J., Humpreys and W. F., Meggers, “Further description and analysis of the first spectrum of xenon,” Bureau Standards J. Res. 10, 139–149, 1932.Google Scholar
[4] J. P., Gordon, H. J., Zeiger, and C. H., Townes, “Molecular microwave oscillator and new hyperfine structure in the microwave spectrum of NH3,” Phys. Rev. 95, 282–284, 1954.Google Scholar
[5] J. P., Gordon, H. J., Zeiger, and C. H., Townes, “The maser – new type of microwave amplifier, frequency standard, and spectrometer,” Phys. Rev. 99, 1264–1274, 1955.Google Scholar
[6] J., Weber, “Amplification of microwave radiation by substances not in thermal equilibrium,” Trans. IRE Professional Group Electron Devices 3, June, 1–4, 1953.Google Scholar
[7] N. G., Basov and A. M., Prokhorov, “Theory of a molecular oscillator and a molecular power amplifier,” Dokl. Akad. Nauk SSSR 101, 47–49, 1955.Google Scholar
[8] T., Maiman, “Stimulated optical radiation in ruby,” Nature 187, 493–494, 1960.Google Scholar
[9] A., Javan, W. R., Bennett Jr. and D. R., Herriott, “Population inversion and continuous optical maser oscillation in a gas discharge containing a He-Ne mixture,” Phys. Rev. Lett. 6, 106–110, 1961.Google Scholar
[10] J. Clerk, Maxwell, A Treatise on Electricity and Magnetism, Oxford: Clarendon Press, 1873 (now available in an edition edited by T. F. Torrance, Edinburgh: Scottish Academic Press, 1982).Google Scholar
[11] R., Kohlrausch and W. E., Weber, “Über die Elektrizitätsmenge, welche bei galvanischen Strömen durch den Querschnitt der Kette fließt,” Ann. Phys. 99, 10–25, 1856.Google Scholar
[12] E. B., Rosa and N. E., Dorsey, “A new determination of the ratio of the electromagnetic to the electrostatic unit of electricity,” Bull. Bureau of Standards 3, 433–540, 1907.Google Scholar

Save book to Kindle

To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×