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Laser safety level and protection

Lasers are widely used in life, such as laser beauty and laser medical treatment. Industrial applications are more common, acrylic, MDF wood, PVC board, etc. Lasers are used in hardware, electronic appliances, and even children’s laser brushes.

The above are just some of the more common application areas of lasers. In fact, the scope of laser applications is far more than that. Laser breeding, laser collimation, laser video disc... Lasers can be seen almost everywhere in life.

What is laser
Laser refers to a coherent enhanced photon beam produced by stimulating atoms to cause electrons to migrate and release radiation energy. Depending on the excitation device, lasers of different wavelengths (colors) and power can be produced. Generally divided into 4 levels according to its safety level

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What are the laser grades
Level 1: It is safe in the device. It is usually because the beam is completely enclosed, such as in a CD player.
Level 2: It is safe under normal conditions of use, and the blinking reflex of the eyes can avoid injury. Such devices usually have power below 1mW, such as laser pointers.
Level 3 a/R: The power usually reaches 5mW, and there is a small risk of harm to the eyes within the time of blinking reflection. Looking at this beam for a few seconds can cause immediate damage to the retina. Class 3b/B: Will cause immediate damage to the eyes under exposure.
Level 4: The laser will burn the skin. In some cases, even the scattered laser can cause damage to the eyes and skin. Many industrial and scientific lasers belong to this class.

But even the first class laser is considered potentially dangerous. Low-power irradiation of a few milliwatts is enough to endanger the vision of the human eye.

Laser damage
If the wavelength of the laser is within the range where the cornea and lens can be well focused on the retina, it means that this divergent laser with low coherence will be focused by the eye on a very small area on the retina, just a few seconds or less Time, it will cause local burning and permanent damage to the retina, which may lead to retinal perforation (a hole in the omentum) and severe retinal detachment.

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protection goggle

Protective glasses should be protected against the laser type, how many nm band lasers, and wear the corresponding protective glasses.

The criterion for judging the protection is the original laser energy, what is the remaining laser energy after passing through the protective glasses, optically called the OD value, if it is described by electromagnetic waves, it is called dB. In popular terms, it is called down to a few percent or a few thousandths of the original.

Protection is for specific wavelength bands, usually by coating. For example, the thickness of the coating is usually a positive integer multiple of a quarter of the wavelength, so that the interference effect of the laser can offset the laser energy to achieve the protective effect. There is also laser protection for all wavelengths, preventing all lasers after a certain wavelength.