lasere

Lasere are devices that emit light through amplification by stimulated emission of radiation. In English, the common term is laser, with the plural lasers; lasere is the form used in some languages to refer to such devices. A laser produces light that is highly collimated, coherent, and typically of a narrow spectral bandwidth, enabling precise and directed energy delivery.

A laser system consists of a gain medium, a pump source to excite the medium, and an optical resonator such as mirrors. The pump excites atoms or molecules in the gain medium, and stimulated emission causes photons to be emitted in phase and in the same direction. The resonator reinforces the light to produce a strong, monochromatic beam. The choice of gain medium determines the emission wavelength, resulting in a wide range from ultraviolet to infrared.

Historically, the first operational laser was demonstrated in 1960 by Theodore Maiman, using a ruby crystal. The concept of stimulated emission was established earlier by Einstein, and the technology rapidly diversified into many architectures.

Common types include solid-state lasers (for example, ruby and Nd:YAG), gas lasers (such as CO2 and He‑Ne), dye lasers, semiconductor (diode) lasers, and fiber lasers. Each type offers specific wavelength ranges, power levels, and beam qualities suited to different applications.

Applications span industry, medicine, communications, science, and consumer electronics. Lasers are used for cutting and welding, eye surgery and dermatology, barcode and data reading, optical communication, spectroscopy, and precision metrology. Safety considerations are important, as laser beams can damage eyes and skin; proper controls, labeling, and protective equipment are standard in professional settings.