A Brief History of the Laser
Lasers in this day and age are widespread and omnipresent, even if you’re not entirely aware of it. They exist in CD players, DVD players, fiber optics, and amplifiers and loudspeakers and are used prominently in medicine—LASIK surgery and laser fat removal, for instance—but there was a lot of work that went into the development of lasers to make them such a ubiquitous element of everyday life. Let’s take a brief look at the history of lasers.
While he didn’t come up with lasers himself, Max Planck developed the backbone of quantum theory that would eventually lead to the creation of the first laser. Planck worked in thermodynamics and was particularly interested in radiation that absorbed all wavelengths of light.
In 1900, Planck published a work that described the relationship between radiation frequency and energy. He deduced that energy could only be absorbed or emitted in separate chunks, which he dubbed quanta. Quanta became the elementary unit for energy.
Based on Planck’s work, Einstein released his paper about the photoelectric effect in 1905. The photoelectric effect proposed that light also delivers its energy in chunks or clusters. He called these discrete particles photons.
In 1917, Einstein proposed stimulated emission, the process that would eventually make the laser and cold laser possible. Stimulated emission basically proposed that electrons could emit light of a particular wavelength.
Charles Townes and the Maser
In 1951, Charles Townes conceived the idea of the maser (microwave amplification by stimulated emission of radiation). Three years later, with help from Arthur Schawlow, Charles Townes invented a functioning maser that used ammonia gas and microwave radiation. The maser radiated at a wavelength of 1 cm and generated about 10 nanowatts of power.
In 1959, Townes and Schawlow received a patent for the maser. Eventually, the maser was used as an ultrasensitive detector in space research and to amplify radio signals.
The maser was the first device that, based on Einstein’s predictions, used stimulated emission to generate and amplify electromagnetic waves. While it didn’t use visible light, the maser’s technology was surprisingly close to what would be used in laser body sculpting today.
Theodore Maiman and Gordon Gould
A physicist at Hughes Research Labs, Theodore Maiman invented the first successful optical laser using a cylinder of synthetic ruby that was 1 cm in diameter and 2 cm in length. Maiman used a set of photographic flashlamps for his laser’s pump source.
However, some controversy purports that Gordon Gould was actually the first to invent an optical laser. Gould, a doctoral student at Columbia, was the first to use the term/acronym laser and built his own optical laser but fought a lengthy patent battle that wasn’t won until 1977.
Through it all came the first few steps at creating the optical laser we know and love.