Light Emitting Diodes, or LEDs, have been around for the past 30 years. Once used only for indicators lights, breakthroughs in LED technology are generating development of energy-efficient solid state lighting (SSL) which is now being hailed as the “light of the 21 st century.” Solid state lighting refers to the use of high brightness light emitting diodes (HB LEDs) as light sources to replace conventional incandescent and fluorescent lamp technologies.
The majority of solid-state lighting applications to date have involved colored light. Beyond indicator lights, typical applications have included automobile brake lights, traffic signals, exit signs, and flashlights. However, white LEDs, introduced in the late 1990s, have made tremendous progress in efficiency and lumen output and as a result white LEDs are now poised to enter the $12 billion market for general illumination.
