Lasers were developed in an effort to better understand the origin and nature of electromagnetic radiation. They produce a powerful beam of light that does not exist on its own. The idea for the laser began emerging as long ago as 1905 when Albert Einstein suggested the stimulated emission of light. Light sources such as candles, florescent substances, and light bulbs, give off packets of energy, called photons, when their atoms (the tiny building blocks of life) are excited by energy. Einstein suggested that these atoms could also be artificially stimulated to emit photons. This stimulated emission of light would produce a highly concentrated, bright, and powerful beam of light that could be used in many tasks.

     Even though the principals for building a laser were known in the early 1900s, it was not attempted to be built a laser until much later because it would be too expensive and difficult at that time since the advanced machinery that was needed to achieve this did not exist. It was not until in the 1950s that the "stage was set" to build a laser.

     Charles Townes, a scientist, wanted to see if microwaves, which are very similar to light, might be simulated to produce an amplified beam by the process that Einstein described. Townes was successful in 1954 when he constructed what he called the maser (microwave amplification by stimulated emission of radiation). The maser amplifies the number of photons that cause microwaves. In Townes maser ammonia gas molecules where pumped through the maser where excited molecules were separated from unexcited ones. The excited ones flow into the resonator (vibrating chamber) where they begin to emit microwave photons. More and more microwaves are produced which leave the maser as an amplified microwave beam.

     After the invention of the maser many scientists started to become interested in the idea of building an optical maser which soon received the name of laser (light amplification by stimulated emission of radiation). Townes paired with Arthur Schawlow, two Soviets, Nikolai Basov and Aleksander Prokhorov, as well as Gordon Gould were all interested in developing a light-amplifying device. All of them knew that there were three essential ingredients in making a laser: a florescent material that would emit light when stimulated by radiation from an external energy source, two facing mirrors on the sides of the florescent material, and external energy source.

     Theodore Maiman was the first to successfully assemble an optical laser. In 1960, Maiman produced a ruby laser. In it a strobe lamp is coiled around the core, a rod of ruby that has mirrors at its ends, one of which is only partially solid. As the strobe light flashes it excites the ruby atoms that in turn emit photons. The photons are reflected back and forth by the mirrors until they pass through the partially solid mirror. This results in brief bursts of pure red laser light that was millions of times brighter than the sun.

     Maiman published his successful experiment but its importance was not realized immediately. Slowly other scientists began to build their own lasers and they quickly found out that materials other than ruby could be used as the core. In 1961, Ali Jaran produced a laser with helium-neon gas in a hollow tube at the core (see diagram below). This laser emitted continuous red laser light. In 1962 a laser was made with galliu arsenide (a kind of crystal). This laser proved to produce infrared light more efficiently. And so, with more and more experiments the era of the lasers was born.