The laser is a device that makes a very narrow, powerful beam of light that can be used for cutting things, light shows, and for medical operations. The term Laser is an acronym that stands for Light Amplification by Stimulated Emission of Radiation. “In 1954, Charles Townes and Arthur Schawlow invented the maser (microwave amplification by stimulated emission of radiation), using ammonia gas and microwave radiation - the maser was invented before the (optical) laser. The technology is very close but does not use a visible light. “In 1960, Theodore Maiman invented the ruby laser, considered to be the first successful optical or light laser.” The first person to use the term laser was Gordon Gould. Prior to Maiman's laser, Gould made a laser, but his patent was denied and Gould did not get recognition until 30 years after. He was a student of Charles Townes, the inventor of the maser.
Theodore Maiman
"In 1961, Dr. Goldman became the first researcher to use a laser to treat a human skin disease when he treated melanoma. The method later became popular in removing birthmarks and tattoos without leaving much scarring."
Arthur Schawlow
Arthur Schawlow worked with Charles Townes to invent the maser. In 1957 they published the first guide to the construction of the Laser. The 1960 patent of the laser has both Schawlow's and Townes' names.