The light produced by a laser is in the form of a narrow beam. It can be concentrated on tiny spots. Irradiance of a high degree can, therefore, be achieved; with the concept of irradiance described as the power of electromagnetic radiation per unit area at a given surface. Another way in which the laser beam is launched/directed is that in which low divergence is achieved. It allows the power to concentrate even at a longer distance from the source of light. History Theodore Maiman is credited with the demonstration of a working laser for the first time in 1960. He gave the demonstration at the Hughes Research Laboratories. Albert Einstein talked about the subject of lasers in one of his papers in 1917. Einstein also spoke about Rudolph W. Landenburg in this paper. Landenburg was the person who had supported/confirmed the existence of emissions produced by stimulation in 1928. Valentin A. Fabrikant, in 1939, made a prediction about the use of such kind of stimulation in reality. The serious study of laser technology started in the year 1957, and was carried out by Arthur Leonard Schawlow and Charles Hard Townes. The use of laser technology in barcode applications for departmental stores and supermarkets began in the year 1974. Applications The laser beam is used in many different fields. It is commonly used in the operation of CDs and DVDs. Computer mice, optical scanners, laser pointers, and printers are other devices in which the laser beam finds application. It is also used in the production of holograms. The survey of land required in building construction is carried out by means of laser beams. In the medical field, surgeries and cosmetic procedures are conducted with the help of laser beams. A microwave amplifier that worked on the principles of laser was produced by Herbert J.Zeiger and James P.Gordon, in 1953. Welding It is a technique used to weld/join together metal pieces. The benefit of using a laser beam for welding is that the source of heat can be concentrated in a narrow space; it allows for deep welds. The success rate of welding too is high. This welding process mostly finds applications in the automotive industry. Gas-state and solid-state are two types of lasers used in welding. In solid-state lasers chromium, synthetic ruby, and aluminum oxide are the media used, while a mixture of nitrogen, helium, and carbon dioxide is used in gas-state lasers. The purpose of both gas-state and solid state lasers is, however, the same, i.e., production of stimulated photons. Divergence The rate at which a laser beam expands from the beam waist is referred to as its divergence. A beam with a low divergence is considered better from the point of operation of these devices. Different techniques, such as scanning pinholes, variable apertures, CCD relays, and knife edges are used in the measurement of divergence. The laser beam is an important invention and has great scope for technological development. Improvements in fields like medicine, entertainment, defense, computing, telecommunications, etc., can be brought about by means of this technology. Even today, we can find many applications of this technology.