Section Overview:
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.
Review Articles
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.
Interactive Tutorials
Lightning: A Natural Capacitor
Lightning is one of the naturally occurring mechanisms that provided early mankind with the ability to understand and harness fire.
Color Temperature
Investigate the apparent "color" of a virtual radiator as it is slowly heated through a wide temperature range by external energy.
Compact Disk Lasers
Explore the interactions between a laser beam and the surface of a spinning compact disk showing variations of how light is scattered or reflected back into a detector.
Light Emitting Diodes
Light emitting diodes (LEDs) are a source of light with a high luminescence efficiency based on a twin-element semiconductor diode encased in a clear epoxy dome.
Argon-Ion Lasers
Part of the well-explored family of ion lasers, the argon-ion laser operates in the visible and ultraviolet spectral regions by utilizing an ionized species of the noble gas argon.
Nd:YLF Mode-Locked Pulsed Lasers
Many applications, such as illumination techniques in fluorescence optical microscopy, require a reliable power laser source enabling efficient frequency conversions.
Diode Lasers
Semiconductor diode lasers having sufficient power output to be useful in optical microscopy are now available from a host of manufacturers.
Ti:Sapphire Mode-Locked Lasers
The self mode-locked Ti:sapphire pulsed laser is currently one of the preferred laser excitation sources in a majority of multiphoton fluorescence microscopy investigations.