Radiant emissivity

This is the fourth installment of lecture demonstrations on radiation exchange, by J.H. Taylor of Rhodes College in Memphis, Tenn. The May issue will feature the first article in a series on applications of radiation exchange, beginning with an examination of the infrared spectrum of a block of ice.

by J. H. Taylor

Standards and terminology

This month we will try to stand back and look at the optical standardization forest instead of the trees that we have been addressing for so many months. One of the areas that keeps cropping up as we discuss trees is the matter of terminology. In our own field we generally understand the jargon and do not give a second thought when we write down such terms as "angular magnification" or "diopter."

by Robert E. Parks

Fiber-optic measurements

Some fundamental optical quantities such as optical power level are important in fiber-optic systems. However, other factors important in fiber-optic systems, such as transmission bandwidth and numerical aperture, are measured only indirectly, by measuring more fundamental quantities such as power distribution in time and space, and inferring other characteristics from them.

by Jeff Hecht