A dazzler is a non-lethal weapon which uses intense directed radiation to temporarily disable its target with flash blindness. Targets can include sensors or human vision.
Ultraviolet (UV) designates a band of the electromagnetic spectrum with wavelength from 10 nm to 400 nm, shorter than that of visible light but longer than X-rays. UV radiation is present in sunlight, and contributes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack the energy to ionize atoms, it can cause chemical reactions and causes many substances to glow or fluoresce. Consequently, the chemical and biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules.
Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore lower energy, than the absorbed radiation. The most striking example of fluorescence occurs when the absorbed radiation is in the ultraviolet region of the spectrum, and thus invisible to the human eye, while the emitted light is in the visible region, which gives the fluorescent substance a distinct color that can be seen only when exposed to UV light. Fluorescent materials cease to glow nearly immediately when the radiation source stops, unlike phosphorescent materials, which continue to emit light for some time after.
It is intended to have three key advantages over previous laser dazzlers which operate in visible wavelengths:
the power levels used can be lower, so there is in theory less risk of eye damage;
the location of the laser is not apparent to the target; and
it has a wide angle of effectiveness.
However, the proposal has been seriously questioned. New Scientist quoted two experts, Tom van den Berg of the Netherlands Ophthalmic Research Institute and Bill Stark of Saint Louis University, as suggesting that at the requisite power levels the use of UV wavelengths is in itself questionable and could damage the lens, almost definitely causing cataracts.
New Scientist, first published on 22 November 1956, is a weekly, English-language magazine that covers all aspects of science and technology. New Scientist, based in London, publishes editions in the UK, the United States, and Australia. Since 1996 it has been available online.
Saint Louis University (SLU) is a private Roman Catholic research university with campuses in St. Louis, Missouri, United States, and Madrid, Spain. Founded in 1818 by Louis Guillaume Valentin Dubourg, it is the oldest university west of the Mississippi River and the second-oldest Jesuit university in the United States. It is one of 28 member institutions of the Association of Jesuit Colleges and Universities. The university is accredited by the North Central Association of Colleges and Secondary Schools. SLU's athletic teams compete in NCAA's Division I and are a member of the Atlantic 10 Conference. It has an enrollment of 12,649 students, including 7,984 undergraduate students and 4,665 graduate students that represents all 50 states and more than 70 foreign countries. Its average class size is 23.8 and the student-faculty ratio is 9:1.
A cataract is a clouding of the lens in the eye which leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colors, blurry or double vision, halos around light, trouble with bright lights, and trouble seeing at night. This may result in trouble driving, reading, or recognizing faces. Poor vision caused by cataracts may also result in an increased risk of falling and depression. Cataracts cause half of all cases of blindness and 33% of visual impairment worldwide.
In addition Professor Stark (an expert in the effects of UV light on eyes) questioned whether the idea could work at all: "My experience suggests that such fluorescence does not cause significant amounts of glare."
The electromagnetic spectrum is the range of frequencies of electromagnetic radiation and their respective wavelengths and photon energies.
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term "laser" originated as an acronym for "light amplification by stimulated emission of radiation". The first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow.
At sufficiently high flux levels, various bands of electromagnetic radiation have been found to cause deleterious health effects in people. Electromagnetic radiation can be classified into two types: ionizing radiation and non-ionizing radiation, based on the capability of a single photon with more than 10 eV energy to ionize oxygen or break chemical bonds. Extreme ultraviolet and higher frequencies, such as X-rays or gamma rays are ionizing, and these pose their own special hazards: see radiation and radiation poisoning. The last quarter of the twentieth century saw a dramatic increase in the number of devices emitting non-ionizing radiation in all segments of society, which resulted in an elevation of health concerns by researchers and clinicians, and an associated interest in government regulation for safety purposes. In the United States, this has resulted in legislation such as the Radiation Control for Health and Safety Act of 1968 and the Occupational Safety and Health Act of 1970. By far the most common health hazard of radiation is sunburn, which causes over one million new skin cancers annually in United States.
Sunglasses or sun glasses are a form of protective eyewear designed primarily to prevent bright sunlight and high-energy visible light from damaging or discomforting the eyes. They can sometimes also function as a visual aid, as variously termed spectacles or glasses exist, featuring lenses that are colored, polarized or darkened. In the early 20th century, they were also known as sun cheaters.
A blacklight, also referred to as a UV-A light, Wood's lamp, or ultraviolet light, is a lamp that emits long-wave (UV-A) ultraviolet light and very little visible light.
A directed-energy weapon (DEW) is a ranged weapon that damages its target with highly focused energy, including laser, microwaves and particle beams. Potential applications of this technology include weapons that target personnel, missiles, vehicles, and optical devices.
Fluorescence spectroscopy is a type of electromagnetic spectroscopy that analyzes fluorescence from a sample. It involves using a beam of light, usually ultraviolet light, that excites the electrons in molecules of certain compounds and causes them to emit light; typically, but not necessarily, visible light. A complementary technique is absorption spectroscopy. In the special case of single molecule fluorescence spectroscopy, intensity fluctuations from the emitted light are measured from either single fluorophores, or pairs of fluorophores.
Laser safety is the safe design, use and implementation of lasers to minimize the risk of laser accidents, especially those involving eye injuries. Since even relatively small amounts of laser light can lead to permanent eye injuries, the sale and usage of lasers is typically subject to government regulations.
A fluorescence microscope is an optical microscope that uses fluorescence and phosphorescence instead of, or in addition to, scattering, reflection, and attenuation or absorption, to study the properties of organic or inorganic substances. "Fluorescence microscope" refers to any microscope that uses fluorescence to generate an image, whether it is a more simple set up like an epifluorescence microscope or a more complicated design such as a confocal microscope, which uses optical sectioning to get better resolution of the fluorescence image.
A laser pointer or laser pen is a small handheld device with a power source and a laser diode emitting a very narrow coherent low-powered laser beam of visible light, intended to be used to highlight something of interest by illuminating it with a small bright spot of colored light. Power is restricted in most jurisdictions not to exceed 5 mW.
Yttrium aluminum garnet (YAG, Y3Al5O12) is a synthetic crystalline material of the garnet group. It is a cubic yttrium aluminum oxide phase, with other examples being YAlO3 in a hexagonal or an orthorhombic, perovskite-like form, and the monoclinic Y4Al2O9.
The ultraviolet index or UV Index is an international standard measurement of the strength of sunburn-producing ultraviolet (UV) radiation at a particular place and time. The scale was developed by Canadian scientists in 1992, and then adopted and standardized by the UN's World Health Organization and World Meteorological Organization in 1994. It is primarily used in daily forecasts aimed at the general public, and is increasingly available as an hourly forecast as well.
Chirped pulse amplification (CPA) is a technique for amplifying an ultrashort laser pulse up to the petawatt level with the laser pulse being stretched out temporally and spectrally prior to amplification.
A ruby laser is a solid-state laser that uses a synthetic ruby crystal as its gain medium. The first working laser was a ruby laser made by Theodore H. "Ted" Maiman at Hughes Research Laboratories on May 16, 1960.
Ultraviolet photography is a photographic process of recording images by using light from the ultraviolet (UV) spectrum only. Images taken with ultraviolet light serve a number of scientific, medical or artistic purposes. Images may reveal deterioration of art works or structures not apparent under visible light. Diagnostic medical images may be used to detect certain skin disorders or as evidence of injury. Some animals, particularly insects, use ultraviolet wavelengths for vision; ultraviolet photography can help investigate the markings of plants that attract insects, while invisible to the unaided human eye. Ultraviolet photography of archaeological sites may reveal artifacts or traffic patterns not otherwise visible.
Under certain conditions, laser light or other bright lights directed at aircraft can be a hazard. The most likely scenario is when a bright visible laser light causes distraction or temporary flash blindness to a pilot, during a critical phase of flight such as landing or takeoff. It is far less likely, though still possible, that a visible or invisible beam could cause permanent harm to a pilot's eyes. Although laser weapons are under development by armed forces, these are so specialized, expensive and controlled that it is improbable for non-military lasers to cause structural damage to an aircraft.
Non-ionizingradiation refers to any type of electromagnetic radiation that does not carry enough energy per quantum to ionize atoms or molecules—that is, to completely remove an electron from an atom or molecule. Instead of producing charged ions when passing through matter, non-ionizing electromagnetic radiation has sufficient energy only for excitation, the movement of an electron to a higher energy state. In contrast, ionizing radiation has a higher frequency and shorter wavelength than nonionizing radiation, and can be a serious health hazard; exposure to it can cause burns, radiation sickness, cancer, and genetic damage. Using ionizing radiation requires elaborate radiological protection measures, which in general are not required with nonionizing radiation.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
