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Optical wireless communications (OWC) is a form of optical communication in which unguided light is used "in the air" (or in outer space), without an optical fiber. Visible, infrared (IR), or ultraviolet (UV) light is used to carry a wireless signal. It is generally used in short-range communication; extensions exist for long-range and ultra ...
Halogen lamps with fused quartz envelopes are used as inexpensive UV light sources in the near UV range, from 400 to 300 nm, in some scientific instruments. Due to its black-body spectrum a filament light bulb is a very inefficient ultraviolet source, emitting only a fraction of a percent of its energy as UV, as explained by the black body ...
Blacklight fluorescent tubes. The violet glow of a blacklight is not the UV light itself, but visible light that escapes being filtered out by the filter material in the glass envelope. A blacklight, also called a UV-A light, Wood's lamp, or ultraviolet light, is a lamp that emits long-wave ultraviolet light and very little visible light.
UV-B lamps are lamps that emit a spectrum of ultraviolet light with wavelengths ranging from 290–320 nanometers. This spectrum is also commonly called the biological spectrum due to the human body's sensitivity to light of such a wavelength. [1] UV-B light does not tan the skin very much, compared to the UV-A lamps that are used in tanning beds.
An optical filter can be used to block out visible light and near-ultraviolet light. It is important to have a high transmittance within the solar-blind spectrum, but to strongly block the other wavelengths. [2] Interference filters can pass 25% of the wanted rays, and reduce others by 1000 to 10,000 times.
Low power consumption of semiconductors introduce UV disinfection systems that utilized small solar cells in remote or Third World applications. [2] By 2019, LEDs made up 41.4% of UV light sales, up from 19.2% in 2014 [3] The UV-C LED global market is expected to rise from $223m in 2017 to US$991m in 2023. [4]
is a key reaction in the formation of tropospheric ozone. [16] The formation of the ozone layer is also caused by photodissociation. Ozone in the Earth's stratosphere is created by ultraviolet light striking oxygen molecules containing two oxygen atoms (O 2), splitting them into individual oxygen