Free-space optical communication in the context of IrDA

A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word laser originated as an acronym for light amplification by stimulated emission of radiation. The first laser was built in 1960 by Theodore Maiman at Hughes Research Laboratories, based on theoretical work by Charles H. Townes and Arthur Leonard Schawlow and the optical amplifier patented by Gordon Gould.

A laser differs from other sources of light in that it emits light that is coherent. Spatial coherence allows a laser to be focused to a tight spot, enabling uses such as optical communication, laser cutting, and lithography. It also allows a laser beam to stay narrow over great distances (collimation), used in laser pointers, lidar, and free-space optical communication. Lasers can also have high temporal coherence, which permits them to emit light with a very narrow frequency spectrum. Temporal coherence can also be used to produce ultrashort pulses of light with a broad spectrum but durations measured in attoseconds.

IrDA is a wireless standard designed for data transmission using infrared (IR). Infrared ports for this purpose have been implemented in portable electronic devices such as mobile telephones, laptops, cameras, printers, and medical devices. The main characteristics of this kind of wireless optical communication are short-range, physically secure and bidirectional data transfer, at serial cable speeds, with a line-of-sight using point-and-shoot principles. IrDA has been made dormant by newer improved technologies like Bluetooth.