Is Infrared Light Harmful?
On its own, natural radiation is usually safe. However, any form of radiation is considered dangerous when concentrated into small beams of significant power.
What are Infrared rays?
Infrared light rays are a type of radiant energy that our eyes cannot see, but which we feel as heat. Any matter in the universe emits infrared light, including two common items in daily life- the Sun and fire.
In order to understand infrared light rays, we first need to look at the electromagnetic spectrum in which it exists. Electromagnetic radiation is produced when electric and magnetic fields are disturbed. Radiation caused by electrons is released as photons, which are particles of light energy traveling in waves at the speed of light. The electromagnetic spectrum categorizes the types of energy based on their wavelength.
Infrared light is a category of radiation on the electromagnetic spectrum, defined as light energy between the wavelengths of 0.7 micrometers (0.00002756 inches) and 0.1 millimeters (0.0039 inches). Infrared light has a longer wavelength than visible light, but a lower frequency. The shorter infrared waves known as “near-infrared” do not emit heat that is easily detected. They are commonly used by devices such as remote controls. The longer infrared waves known as “far-infrared” are close to the microwave category of the electromagnetic spectrum. They could be perceived as intense heat, including that emitted by the Sun.
How is infrared light produced?
Much of infrared radiation (IR) is produced by heat. Atoms are constantly vibrating or moving, possessing different levels of energy. When atoms receive a lot of energy, they leave the ground-state energy level and reach an excited level. Electrons orbiting the nucleus of the atom become energized, and eventually release energy as photons or light particles. This is where you may observe heating elements changing color to red, such as those on an electric stove.
In short-range communication devices, light emitting diodes (LEDs) produce infrared light by focusing infrared radiation through a plastic lens. The receiver then uses a silicon photodiode to convert infrared light to electricity. This mechanism is widely used for remote controls.
Is infrared radiation dangerous?
On its own, natural radiation is usually safe. However, any form of radiation is considered dangerous when concentrated into small beams of significant power. Imagine placing your hands on a hot iron- you are sure to suffer from burns! By the same principle, looking at a laser light or working with molten metals in the long-term without protective eyewear, could result in damage to your health.
Dangers of infrared light
Infrared light is widely used in factories and for heating and lasers. The near-infrared waves do not feel hot, and pose a danger to the skin and eyes. Human skin feels pain when exposed to excessive heat, while the eyes may not be as sensitive. Thus, closing your eyes may not help in reducing damage from infrared rays. Long-term exposure to infrared radiation has been blamed for causing damage to the lens, retina and damage. This leads to conditions such as retinal burns, cataracts and corneal ulcers.
Know about dangers of infrared pointers
As mentioned in our earlier article, infrared laser pointers may be dangerous above a certain class rating. Radiation from the infrared laser can temporarily disturb your vision. In severe cases, there could be permanent harm, while prolonged exposure even to mild levels of infrared light may cause harm to your health. In order to avoid this risk, consider buying a recommended presentation pointer that is safe for consumer use!
A brief history of Lasers
Laser technology is now well over 50 years old. In 1900, the physicist Max Planck deduced that energy could be absorbed or emitted in chunks. He later won a Nobel Prize for this discovery. In 1905, Albert Einstein suggested that light energy is emitted in particles called photons. He then proposed a process whereby electrons could be stimulated to emit light in specific wavelengths.
In the 1950s, Charles Hard Townes, Herbert J. Zeiger and James P. Gordon developed a “maser” device based on Einstein’s theories. The word “maser” stood for “microwave amplification by stimulated emission of radiation”. This was the precursor to the modern laser. Townes and his brother-in-law developed an optical maser device for Bell Labs. Separately, Gordon Gould wrote down his ideas for a laser in his notebook, and applied for a joint patent with his employer. This resulted in a patent dispute that lasted over 30 years.
From the 1960s onwards, many laser devices were developed for commercial applications. Innovations such as laser diodes, medical tools, laser discs, fiber optics, cutting tools, barcode scanners and integrated circuits made use of laser technology. New devices were created and processes were improved, contributing greatly to society as we know it today.
Do lasers emit radiation?
Not many people know this, but the word ‘laser’ actually stands for “Light Amplification by the Stimulated Emission of Radiation”! The answer to the above question is definitely “Yes”. The main difference between lasers is the type of radiation emitted, which could be visible or invisible.
The most basic form of lasers comprises a sealed tube with a pair of mirrors, and a laser medium that uses some form of energy to produce radiation. This radiation could be visible light, ultraviolet or infrared radiation. Laser radiation can be emitted in a tight beam, posing hazards to bystanders. Your eye may focus the laser beam onto a tiny spot on the retina, causing burns or blindness in that spot.