By the beginning of the 20th century, scientists realized that light can be viewed as electromagnetic waves, similar to laser pointer waves, but with a much shorter wavelength. The spectrogram shows various forms of electromagnetic radiation. The only difference between one ray and another is its wavelength. (We can also say that the frequency is different. Frequency is the number of waves that light passes through a point per second as it moves in space.) Plot the spectrum to reduce the wavelength by a large multiple in each major area. Therefore, visible light is 1/100,000 of the "microwave" light length commonly used by radars. Rays with shorter wavelengths can carry more information and more energy.
As early as the 1930s, scientists could already make laser engraver. They have optical technology and theoretical knowledge, but nothing can bring them together. Around 1950, people moved in an unexpected direction. Short-wave radio waves called microwaves can cause clusters of atoms to vibrate in a visible way (a technique called microwave spectroscopy). Radar equipment left over from World War II was redesigned to provide radiation. Many top physicists in the world are considering methods of studying molecular systems by bathing molecules.
When Charles Hard Townes and Arthur Leonard (Bell Laboratories) filed a patent application in 1958, the original name of the laser was "optical laser." They focused on infrared radiation, but turned their attention to visible light. Columbia University graduate student Gordon Gould was writing his doctoral dissertation. When Townes and Gould met, they discussed radiation. In 1958, Gould published the paper "Laser, stimulated emission of amplified light", and the term "laser" was born.
In 1954, Charles Townes and Arthur Schawlow used ammonia and microwave radiation to invent maser (microwave amplification caused by stimulated radiation)-maser was before the invention of (optical) lasers. The technology is very close but does not use visible light. The maser is used to amplify radio signals and as an ultra-sensitive detector for space research.
Many different materials can be used as blue laser pointer. Some lasers emit short pulses like a ruby laser. Other lasers such as HeNe gas lasers or liquid dye lasers emit continuous beams.