A history about laser

In 2020, the laser will celebrate its 60th anniversary. Here, Photonics Media presents a timeline of some of the more notable scientific achievements related to light amplification by stimulated emission of radiation (laser). An interactive version of the laser timeline is also available, as well as an introduction to laser basics detailing how lasers work.

A journey through the light fantastic Laser would not have been possible without the understanding that light is a form of electromagnetic radiation. Max Planck received the Nobel Prize in Physics in 1918 for his discovery of elementary energy quanta. Working in thermodynamics, Planck attempted to explain why "blackbody" radiation, which absorbs all wavelengths of light, did not emit all frequencies of light uniformly when heated.

In his most significant work, published in 1900, Planck deduced the relationship between energy and the frequency of the radiation, essentially saying that energy could only be emitted or absorbed in discrete bits - which he called quanta - even if the bits were very small. His theory marked a turning point in physics and inspired future physicists such as Albert Einstein. In 1905, Einstein published his paper on the photoelectric effect, which proposed that light also delivers its energy in bits, in this case discrete quantum particles now called photons