What is Laser?
Light Amplification by the Stimulated Emission of Radiation, more commonly known as Laser. A laser device emits lights through a process of optical amplification based on the stimulated emission of electromagnetic radiation.
Laser and regular lights are both types of light. Although regular lights and laser lights both share the characteristic of being a type of light, they are actually very different. For instance, ordinary lights produce wide beams of light. Lasers, on the other hand, generates a precise wavelength of light, which is why they’re monochromatic. Additionally, ordinary lights emit light in every direction. As a result, the light fills the entire space where it’s being illuminated. On the other hand, lasers produce one very thin beam of light; hence they only illuminate a small section.
Laser beam stay narrow over far distances and they emit a single color of light.
What is laser used for?
Forms of Laser are widely used within electronic appliances, information technology, manufacturing, communications i.e. fibre optics, medical industries, law enforcement, entertainment, and the military.
Most common Industrial use includes cutting and converting thin materials, welding, material heat treatment, marking parts, engraving, bonding, additive manufacturing, 3D printing processes and laser clinic. Military uses laser for marking targets, guiding munitions, missile defense, electro-optical countermeasures, lidar, blinding troops etc. Ever been fined for speeding via a laser gun? This is LIDAR used by traffic enforcement. Lasers are also used for latent fingerprint detection in the forensic identification field.
Thanks to Laser, healthcare has benefited by innovative treatments, such as laser eye surgery, laser healing, kidney stone treatment, ophthalmoscopy, and cosmetic skin treatments such as acne treatment, cellulite and striae reduction, and hair removal. Lasers are used to treat cancer by shrinking or destroying tumors or precancerous growths. Lasers are more precise than traditional surgery methods and cause less damage, pain, bleeding, swelling, and scarring.
Why Laser harmful? Improperly used laser devices are potentially dangerous. Effects can range from mild skin burns to irreversible injury to the skin and eye. Eyes are in particularly vulnerable and as laser can come in different wavelength, the effect on eyes can be varied depending on the wavelength of the laser.
|Near Ultraviolet Wavelengths||(UVA) 315 – 400 nm||Lens||Long term risk – cataract|
|Far Ultraviolet||(UVB) 280 – 315 nm and (UVC) 100 – 280 nm||Cornea||High absorption can cause a risk of Keratoconjunctivitis|
|Visible||(400 -760 nm) and Near Infrared (760 – 1400 nm)||Retina||Overexposure may cause flash blindness or retinal burns and lesions|
|Far Infrared||(1400 nm – 1 mm)||Cornea||Overexposure to these wavelengths will cause corneal burns|
Laser classification for safety purposes is based on their potential for causing injury to humans’ eyes and skin.
Hence most laser products are required by law to have a label listing the Class.
For visible-beam consumer lasers, there are four main classes. The chart below shows how the eye injury hazard increases as the laser’s power increases.
Safety classes are presented from least dangerous to most dangerous.
|Safety Class||Safe Situation||Unsafe Situation|
|Class 1||For low-emission lasers (≤0.39mW), directly viewing the beam, even for a long time, with the naked eye or with optical instruments Some designs are also intrinsically safe (i.e., the beam can’t be seen)||N/A|
|Class 1M||Directly viewing the beam with the naked eye||Directly viewing the beam with optical instruments|
|Class 2||Accidentally viewing the beam with the naked eye or with optical instruments (the blink reflex limits the exposure since the beam is visible)||Intentionally viewing the beam or the magnified beam for longer than 0.25 seconds|
|Class 2M||Accidentally viewing the beam with the naked eye (the blink reflex limits the exposure when the beam is visible)||Intentionally viewing the beam for longer than 0.25 seconds, or accidentally viewing the beam with optical instruments|
|Class 3R||Brief eye exposure (the acceptable time of exposure depends on the wavelength)||Directly viewing the beam, especially with optical instruments|
|Class 3B||Being exposed to diffuse reflections||Eyes accidentally exposed to the direct beam or specular reflections (dangerous) or skin accidentally exposed to the direct beam (small burns)|
|Class 4||Being outside the nominal ocular hazard area (NOHA)||Eyes, skin, or combustible materials exposed to the direct beam, specular reflections, or diffuse reflections|
How do I protect my eyes from Laser damage?
Protective eyewear is necessary for Class 3 and 4 laser use where irradiation of the eye is possible. Such eye protection should be used only at the wavelength and energy/power for which it is intended. Eye protection include goggles, face shields, over spectacles or prescription eyewear using special filter materials or reflective coatings (or a combination of both) to reduce exposure.
Infield Safety UK has a range of bespoke products that will fulfill the safety requirement depending on the hazards and exposure. All laser safety filters are certified and tested in accordance with the valid standards conferring to International and European Optical and Laser standards (EN 207 / EN 208).