Lasers are everywhere these days – even if you don’t always notice them. They’re in CD and DVD players, fiber optics, amplifiers, loudspeakers, and are widely used in medical procedures like LASIK surgery and laser fat removal. But getting to this point took a lot of work and development. Let’s take a quick look at how lasers came to be.
Max Planck
Max Planck didn’t create lasers himself, but he laid the groundwork with his quantum theory, which was crucial for the development of lasers. He worked in thermodynamics and studied how radiation absorbed all wavelengths of light. In 1900, he published a paper showing the relationship between radiation frequency and energy. He discovered that energy is absorbed or emitted in separate chunks, which he named quanta. These quanta became the basic unit of energy.
Albert Einstein
Building on Planck’s work, Albert Einstein published a paper on the photoelectric effect in 1905. He suggested that light delivers its energy in discrete particles, which he called photons. In 1917, Einstein introduced the concept of stimulated emission, the process that would eventually make lasers possible. This idea suggested that electrons could emit light at a specific wavelength.
Charles Townes and the Maser
In 1951, Charles Townes came up with the idea of the maser (microwave amplification by stimulated emission of radiation). With Arthur Schawlow’s help, Townes created a working maser in 1954 using ammonia gas and microwave radiation. The maser emitted radiation at a 1 cm wavelength and generated about 10 nanowatts of power. Townes and Schawlow obtained a patent for the maser in 1959. Although masers dealt with microwaves rather than visible light, they used similar principles to today’s lasers and were used in space research and radio signal amplification.
Theodore Maiman and Gordon Gould
Theodore Maiman, a physicist at Hughes Research Labs, built the first successful optical laser using a synthetic ruby cylinder as the medium. He used photographic flashlamps as the pump source for his laser. However, there’s some debate over whether Gordon Gould, a doctoral student at Columbia who coined the term “laser,” was the real inventor. Gould created his own optical laser and fought a long patent battle, finally winning in 1977.
So, those are the key steps that led to the amazing optical lasers we use today in many aspects of our lives.