The Evolution of Artificial Light Sources - A Walk through Time
Since the discovery of fire, people have strived to create better and brighter light sources. The origin of artificial light goes all the way back to 500 BC, when bamboo pipes carried natural gas from volcanoes to light the streets of ancient China. Later, the Romans lit the front of their homes with oil lanterns and had special servants who tended to these lanterns. In 1417, the Mayor of London created a law that required all homes have a lantern hung front during the winter.
In the 1700’s, light fixtures were equipped with poorly made oil lamps and candles. Most of these lamps emitted a bad odor and produced a lot of smoke.
It wasn’t until the 1800’s that gas lighting replaced candles and oil lamps. Sir Humphry Davy created the first carbon arc lamp in 1809. Although this lamp was very bright, it was powered by an early battery—which drained very quickly. The first patent for an incandescent lamp was issued in 1841 to Frederick de Moleyns. His lamp was made of glass and a charcoal-based filament, with a partial vacuum. The charcoal caused the lamp to become dingy and dim.
The late 1800’s produced some significant strides in the progression of artificial light sources. A patent for the incandescent lamp with a carbon filament was issued in 1874 to Henry Woodward and Mathew Evens. Woodward and Evens would eventually sell their patent to Thomas Edison. Edison and his group began testing many different materials to create a more efficient carbonized filament. The Edison group discovered that a lamp with a carbonized bamboo filament would burn for up to 1200 hours. For this discovery, Edison received his second incandescent lamp patent. Although Edison did not invent the first light bulb, his “Edison screw-in lamp” is the standard for household lamps even today.
Tungsten filament lamps were developed in 1911 by William D. Coolidge. These lamps would be improved in 1913 by Irving Langmuir, who discovered that filling the glass envelope with an inert gas and twisting the filament improved the performance. Until 1925, all lamps were made of clear glass. Marvin Pipkin invented a way to reduce glare by adding a silica coating to the inside, thus making the first incandescent frosted lamps.
The late 1950’s brought us into the “halogen era.” Scientists at GE brought us the first halogen lamp. Halogen lamps would prove to last longer, but these lamps required proper handling. Scientists continued to work to provide us with more efficient light sources. Edward Hammer created the first spiral compact fluorescent lamp in 1976.
As with many other products, the first LED was discovered by accident. Gary Pittman and James Biard were working on a laser diode when they discovered the first “light emitting diode” (LED) in 1961. The first LED lights were used as indicator and display lights in the early 1970’s. Many scientists would continue working on LED technology by developing different colored diodes.
One more component was needed to develop a bright white LED. It was invented in 1993 by Shuji Nakamura, who developed the first bright blue emitting diode. Today, these diodes are used with different phosphor materials. These materials are used to create different Kelvin temperatures in currently manufactured lamps.
We look forward to where new and continuously improving technology will bring us in the future!