Sources Of Light. Artificial Light Sources

Artificial light source, or, more precisely, artificial sources of optical radiation, is called a device designed to convert any kind of energy into electromagnetic radiation lying in the optical range. The latter is known to be divided into three regions: UV with wavelengths between 1 and 380 nm, visible wavelengths from 380 to 770 nm and infrared at wavelengths from 770 to 106 nm. The emergence of optical radiation (light) is associated with a change in the energy states of valence electrons that are part of the emitting body. The spectrum of light emission is determined by the energy states, which can take electrons as a result of message body of the external energy, ie, the structure of the body, its constituent atoms and molecules. According to the physical nature of optical radiation is divided into thermal radiation and luminescence. Thermal radiation. At the heart of of sources of thermal radiation is the radiation energy, reported the body when heated in some way according to the laws of thermal radiation for high efficiency in the visible spectrum to body heat up to temperatures around 6000 K and strive to ensure that the radiation light source focused on the possibility only in the visible region. When heating solids limit temperature rise is limited their melting temperatures and rapid evaporation of substances currently the highest temperature of heating and lighting efficiency can be obtained by using tungsten carbide and tantalum and hafnium, with still a significant part of radiation lies in the infrared region.

Attempts to significantly increase the light output by increasing the selectivity. Radiation of heated solid bodies have not yet yielded significant results, although in principle the possibility of this direction are available. In contrast to the solid heat of gases and vapors are not limited to the melting temperature and can be carried out to almost any temperature.