![]() ![]() Therefore, a visible, 10 milliwatt/cm2 laser beam would result in a 1000 watt/cm2 exposure to the retina, which is more than enough power density (irradiance) to cause damage. The light entering the eye from a collimated beam in the retinal hazard region is concentrated by a factor of 100,000 times when it strikes the retina. In order for the worst case exposure to occur, an individual's eye must be focussed at a distance and a direct beam or specular (mirror-like) reflection must enter the eye. Within this spectral region collimated laser rays are brought to focus on a very tiny spot on the retina. Of greatest concern, however, is laser exposure in the retinal hazard region of the optical spectrum, approximately 400 nm (violet light) to 1400 nm (near-infrared) and including the entire visible portion of the optical spectrum. At certain wavelengths in the near-ultraviolet region and in the near-infrared region, the lens of the eye may be vulnerable to injury. Figure 2 illustrates the absorption characteristics of the eye for different laser wavelength regions. In the far-ultraviolet and far-infrared regions of the optical spectrum, the cornea absorbs the laser energy and may be damaged. The cornea (the clear, outer front surface of the eye's optics), unlike the skin, does not have an external layer of dead cells to protect it from the environment. It is now widely accepted that the human eye is almost always more vulnerable to injury than human skin. Research relating to injury thresholds of the eye and skin has been carried out in order to understand the biological hazards of laser radiation. The human body is vulnerable to the output of certain lasers, and under certain circumstances, exposure can result in damage to the eye and skin. Lower-power lasers may emit levels of laser light that are not a hazard. Today, most high-power lasers are designed to minimize access to laser radiation during normal operation. In addition to these obvious thermal effects upon tissue, there can also be photochemical effects when the wavelength of the laser radiation is sufficiently short, i.e., in the ultraviolet or blue region of the spectrum. These properties which have been applied to laser surgery and materials processing can also cause tissue damage. If directed, reflected, or focused upon an object, laser light will be partially absorbed, raising the temperature of the surface and/or the interior of the object, potentially causing an alteration or deformation of the material. The laser produces an intense, highly directional beam of light. Laser light is nonionizing and ranges from the ultra-violet (100 - 400nm), visible (400 - 700nm), and infrared (700nm - 1mm). ![]() There are one billion nanometers in one meter. The most common unit used in expressing a laser's wavelength is a nanometer (nm). The color of laser light is normally expressed in terms of the laser's wavelength. Energy moves from one location to another by conduction, convection, and radiation. The use of the word in this context, however, refers to an energy transfer. The term "radiation" is often misinterpreted because the term is also used to describe radioactive materials or ionizing radiation. Energy is amplified to extremely high intensity by an atomic process called stimulated emission. The energy generated by the laser is in or near the optical portion of the electromagnetic spectrum (see Figure 1). Extreme high impact resistance.LASER is an acronym which stands for Light Amplification by Stimulated Emission of Radiation. ![]() Sub-surface printing prevents damage and vandalism. Excellent weathering and UV resistance provides a long-life product.Ģmm transparent, flame retardant polycarbonate. Suitable for both internal and external applications. Luminance properties and performance measured to DIN 67510.Ġ.9mm aluminium with gloss white powder coating. After glow requirements exceed PSPA Class B Standard. Ideally suited to indoor use.įlexible PVC with photo-luminescent pigmentation and self-adhesive backing. High gloss, flexible PVC with self-adhesive backing, suitable for most smooth, dry and clean surfaces. Luminance properties and performance measured to DIN 67510. Lightweight with high impact strength, suitable for internal and external use.ġ.2mm rigid PVC with photo-luminescent pigmentation. Easily drilled, white, glossy, rigid PVC plastic. ![]()
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