The FDA may inspect manufacturers of laser products and require the recall of products that don't comply with federal standards or that have radiation safety defects.
The agency also may test laser products and inspect displays of laser light shows to ensure the public is protected. Producers of laser light shows are required to tell the FDA where they are planning a show so that the agency can inspect it if possible and take action if required. FDA is currently working to identify manufacturers of overpowered green laser pointers and other illegal lasers, and is taking action to prevent these unsafe products from being sold in the United States.
If you have questions about a laser product you are considering purchasing or offering for sale on the Internet, contact the FDA's Center for Devices and Radiological Health at To report Web sites that you suspect are illegally selling laser products, follow the instructions at Reporting Unlawful Sales of Medical Products on the Internet.
What is a laser? Laser What are lasers used for? Why are lasers uniquely hazardous? Two characteristics of laser light contribute to the hazard: Laser light can be emitted in a tight beam that does not grow in size at a distance from the laser. This means that the same degree of hazard can be present both close to and far from the laser.
The eye can focus a laser beam to a very small, intense spot on its retina, which can result in a burn or blind spot. Are all lasers legal for consumer use? What do the different classifications of lasers mean?
Hazard increases if viewed with optical aids, including magnifiers, binoculars, or telescopes. Hazard increases if viewed with optical aids. Risk of injury increases when viewed with optical aids. Considered non-hazardous.
The particular wavelength of light is determined by the amount of energy released when the excited electron drops to a lower orbit. Second, laser light is directional. Whereas a laser generates a very tight beam, a flashlight produces light that is diffuse. Because laser light is coherent, it stays focused for vast distances, even to the moon and back. This laser pulse stimulates the electrons to drop to their lower, or ground, energy states and emit a laser photon of exactly the same wavelength.
An optical switch traps the low-energy laser pulse in the main amplifier for four passes through the laser glass slabs. Mirrors at both ends of the glass amplifier cause the photons to travel back and forth through the glass, stimulating more electrons to drop to their lower energy states and emit photons.
When light electomagnetic energy is shined on a metal surface in a vacuum, it may free electrons from that surface. These electrons can be detected as a current flowing in the vacuum to an electrode. The light was not always strong enough to cause this effect, however. When the scientists made the light brighter, no increase in electrons was seen. Only when they changed the color of the light the wavelength did they see a change in photoemission of electrons.
This was explained by Einstein using a theory that light consists of photons, each with discrete quantum of energy proportional to their wavelength.
For an electron to be freed from the metal surface it would need a photon with enough energy to overcome the energy that bound it to the atom.
So, making the light brighter would supply more photons, but none would have the energy to free the electron. Light with a shorter wavelength consisted of higher energy photons that could supply the needed energy to free the electron.
Now, you ask, "What the heck does this idea of quantum energy have to do with a laser? Well, with this background under our belts we will continue. Laser Components. A substance that when excited by energy emits light in all directions. The substance can be a gas, liquid, or semi-conducting material. The excitation mechanism of a laser is the source of energy used to excite the lasing medium.
Excitation mechanisms typically used are: electricity from a power supply, flash tubes, lamps, or the energy from another laser. T he optical cavity is used to reflect light from the lasing medium back into itself.
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