Sources of Visible Light

Visible light comprises only a tiny fraction of the entire electromagnetic radiation spectrum, yet it contains the only region of frequencies to which the rods and cones of the human eye will respond. The wavelengths that humans are typically able to visualize lie in a very narrow range between approximately 400 and 700 nanometers. Humans can observe and respond to stimuli created by visible light because the eyes contain specialized nerve endings that are sensitive to this range of frequencies. The remainder of the electromagnetic spectrum is invisible to humans.
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Sources of Visible Light

Introduction to Visible Light Sources

Visible light comprises only a tiny fraction of the entire electromagnetic radiation spectrum, yet it contains the only region of frequencies to which the rods and cones of the human eye will respond.

Introduction to Lasers

The special nature of laser light has made laser technology a vital tool in nearly every aspect of everyday life including communications, entertainment, manufacturing, and medicine.

Light Emitting Diode Fundamentals

Recent advances in the design and manufacture of these miniature semiconductor devices called LEDs may result in the obsolescence of the common light bulb, perhaps the most ubiquitous device utilized by modern society.

Light Sources for Optical Microscopy

Explore the progression of external sources for illumination from the early days of microscopists relying on oil lamps or sunlight to the present day where the integral light sources are now controlled to a high degree.

Fluorescence Microscopy Light Sources

Fluorescence microscopy requires the generation of enough excitation light intensity to furnish emission capable of detection. Powerful light sources are needed such as the light sources featured in this article.

Contributing Authors

Kenneth R. Spring - Scientific Consultant, Lusby, Maryland, 20657.
Matthew Parry-Hill, Thomas J. Fellers, and Michael W. Davidson - National High Magnetic Field Laboratory, 1800 East Paul Dirac Dr., The Florida State University, Tallahassee, Florida, 32310.