Townes had predicted that the device’s radiation had extraordinary and useful properties: it would be at a single frequency, as pure as the notes from a tuning fork. That's it. The highly ordered nature of this radiation will make laser masers and later laser pointer important practical uses.
Towns is not alone. Joseph Weber of the University of Maryland independently expressed similar ideas in 1952. Robert Dick of Princeton University took a different path towards the same goal. Neither attempted to build a device. In Moscow, Prokhorov (AM Prokhorov) and Basov (NG Basov) thought in the same direction. They established a militant in 1955.
Lasers are possible due to the way light interacts with electrons. Electrons exist in a specific energy level or characteristic state of the specific atom or molecule. Energy levels can be thought of as rings or orbits around the nucleus. The electrons in the outer ring have a higher energy level than the electrons in the inner ring. Electrons can reach higher energy levels by injecting energy (for example, through a flash lamp). When electrons fall from the outer layer to the inner layer, the "excess" energy is emitted as light. The wavelength or color of the emitted light is precisely related to the energy released. Depending on the specific laser material used, specific wavelengths of light will be absorbed (excited or excited electrons), and specific wavelengths of light will be emitted (when the electrons fall back to their initial energy level).
Researchers at Bell Labs published the theory for producing laser engraver light in 1958. The first laser was manufactured at Hughes Aircraft Corporation in 1960. It used a ruby as the laser medium, light as an energy source, and a mirror to make a resonator. The semiconductor laser was invented in 1962. It uses a semiconductor material similar to that used in transistors and integrated circuits used in laser media. It also uses direct current (DC) generated by the battery as an energy source. It still uses resonant mirrors. The first semiconductor lasers produced invisible infrared radiation.
The semiconductor lasers used in laser pointers are also called diode lasers because they are a type of semiconductor diode. Diodes easily pass current in one direction; they also become smaller and require less energy. They became cheap enough to be used in consumer electronics such as laser pointers in the 1980s. Current laser diodes are the size of blood cells. Compared with resonant cavities, the light they produce is less collimated (moving in one direction) than most blue laser pointer. Therefore, they need some kind of external optics (lens) to focus the light into a tighter beam. Like many semiconductor devices, laser diodes are very precise and need to be protected from the environment and surges.