What is a Green Laser?
A laser works on the principle of Light Amplification by Stimulated Emission of Radiations. Traditional lasers were of red color which offered less strength, versatility and brightness as compared to the advanced green color lasers. A green color laser can be generated within the small body of a miniature flashlight. The green color lies in the visible range and moreover, can easily travel long distances. Therefore, amateur astronomers often use this laser to point at stars and galaxies which are far away in space.
When each and every light wave or a piece of light is collimated (arranged to form a column) into a solid beam, laser action takes place and this wave is a much more powerful light as compared to others. But different colors are determined on the bases of wavelength. The red colored laser lies in the visible spectrum with a wavelength of 650 nanometers but the green color has much more energy, having a wavelength of minuscule 532 nanometers.
As the green color lies nearer to the center of the visible spectrum, it has several advantages over the red color. As the energy of the green color is more, it can travel like a small dot to far off hillsides (9000 feet away) and to low-lying clouds. At night, the green color is also easier to perceive through the eyes as compared to the red color. The green laser is 50 times brighter than the red laser and therefore can form a visible beam even in the presence of dust and fog.
A green laser is also preferred because it doesn’t interfere with the dark adaptations or eyes which become more sensitive to dim color when in persistent darkness. This is why astronomers use green lasers with small telescopes to point to particular constellations, stars and galaxies during star parties. Astronomers use laser beams with strengths around 5 milliwatts but the instruments which are used to deliver laser lights for fun are of 1 milliwatt, to reduce the harm caused by high powered lasers.
The process of generation of a laser beam is very complicated and special type of laser diodes are used to generate it. The right wavelengths are generated by the process of perfect collimation with the help of special crystals which must filter and focus the light. Green lasers are more expensive to produce because the process involves some extra steps while the red laser is formed by direct injection of laser diodes. Based on the controlled reaction, different models are available. Some models allow focusing the green laser to a tiny dot at any distance far from the source and other models release light in spurts and make a dotted line.
Green lasers are much more dangerous as compared to red lasers and should be used with all safety precautions. Never point a laser in the direction where it can encounter people, pets and vehicles. Even a quarter of a second expose to a green laser can permanently damage the retina of an eyeball. Therefore, purchase lasers with a minimum strength required for its usage, and keep it out of the reach of children.
Category: Technology