Ultraviolet light
2024-1-21
Definition:
Invisible light with a wavelength less than about 400nm.
Ultraviolet light is light with a wavelength less than about 400 nm (the lower limit of visible light wavelengths).
There are several different definitions for distinguishing different spectral regions:
Near UV spectrum region from 400nm-300nm. Mid-UV light ranges from 300nm-200nm, while 200nm-10nm belongs to the far UV region. The shorter wavelengths are extreme ultraviolet light (EUV).
Vacuum UV (approximately less than 200nm) refers to the wavelength range usually used by vacuum devices, because light energy of this wavelength is strongly absorbed by air. Vacuum UV includes far UV and extreme ultraviolet light.
UVA represents the wavelength range of 320-400nm, UVB is 280-320nm, and UVC is 200-280nm.
UV light has many uses, such as UV disinfecting water and tools, UV curing adhesives, controlling the quality of many materials and stimulating fluorescence.
Main properties of ultraviolet light
Ultraviolet light differs from visible light in the following two ways:
Its short wavelength can be accurately focused and produce very fine structures (provided a light source with high spatial coherence is used). This can be applied to UV lithography technology to prepare microelectronic devices, such as microprocessors and chips. In the future, microprocessors will require finer structures and require photolithography technology in the EUV region. EUV light sources and their corresponding photoresists are currently being developed.
Its photon energy is higher than the band gap energy of many objects. Therefore, UV light can be absorbed by many substances, and the resulting excitation process can cause changes in the chemical structure of the substance (for example, the breaking of chemical bonds). This can be used in laser material processing (for example, laser etching, pulsed laser deposition, preparation of fiber Bragg gratings), sterilization of water or medical devices. UV light can damage human skin, especially UVC light, which has a bactericidal effect. When UV light interacts with trace amounts of hydrocarbons in the air, it can deposit thin organic layers on nearby surfaces; this light pollution can degrade the quality of the nonlinear crystals in the UV laser source.
Invisible light with a wavelength less than about 400nm.
Ultraviolet light is light with a wavelength less than about 400 nm (the lower limit of visible light wavelengths).
There are several different definitions for distinguishing different spectral regions:
Near UV spectrum region from 400nm-300nm. Mid-UV light ranges from 300nm-200nm, while 200nm-10nm belongs to the far UV region. The shorter wavelengths are extreme ultraviolet light (EUV).
Vacuum UV (approximately less than 200nm) refers to the wavelength range usually used by vacuum devices, because light energy of this wavelength is strongly absorbed by air. Vacuum UV includes far UV and extreme ultraviolet light.
UVA represents the wavelength range of 320-400nm, UVB is 280-320nm, and UVC is 200-280nm.
UV light has many uses, such as UV disinfecting water and tools, UV curing adhesives, controlling the quality of many materials and stimulating fluorescence.
Main properties of ultraviolet light
Ultraviolet light differs from visible light in the following two ways:
Its short wavelength can be accurately focused and produce very fine structures (provided a light source with high spatial coherence is used). This can be applied to UV lithography technology to prepare microelectronic devices, such as microprocessors and chips. In the future, microprocessors will require finer structures and require photolithography technology in the EUV region. EUV light sources and their corresponding photoresists are currently being developed.
Its photon energy is higher than the band gap energy of many objects. Therefore, UV light can be absorbed by many substances, and the resulting excitation process can cause changes in the chemical structure of the substance (for example, the breaking of chemical bonds). This can be used in laser material processing (for example, laser etching, pulsed laser deposition, preparation of fiber Bragg gratings), sterilization of water or medical devices. UV light can damage human skin, especially UVC light, which has a bactericidal effect. When UV light interacts with trace amounts of hydrocarbons in the air, it can deposit thin organic layers on nearby surfaces; this light pollution can degrade the quality of the nonlinear crystals in the UV laser source.
