Understand the importance of laser safety classifications and how they help mitigate potential harm. Learn all about LiDAR laser safety in this comprehensive guide.
Since the early 1970s, lasers have been categorized into four main safety classes and several subclasses based on wavelength and maximum output power. These classifications are crucial in understanding how likely a laser is to cause harm to humans. The laser safety classification system was revised in 2002 to reflect updated knowledge about lasers and their risks, which often resulted in lasers being classified as lower-risk than previously believed.
The revised system includes the following laser safety classes:
- Class 1 lasers are generally considered safe, provided the laser is not focused.
- Class 2 lasers operate between 400-700 nm (visible spectrum). These are generally safe because the natural blink reflex protects the eye from prolonged exposure. Class 2 lasers are limited to 1 mW of continuous wave (cw) power or less.
- Class 3R lasers have power outputs up to 5 mW cw and are safe if handled with care.
- Class 3B lasers require safety precautions like goggles as they can emit up to 30 mW of power.
- Class 4 lasers are the most dangerous, capable of burning skin and damaging eyes, and require strict safety protocols.
Many laser pointers sold on the Internet exceed the safe 5 mW threshold, and users are advised to be cautious. For LiDAR, which often operates at higher power levels, these classifications are important, but Maximum Permissible Exposure (MPE) values, which are based on energy per unit area (J/cm²), are even more critical for eye safety.
While laser classification gives a general idea of laser risks, the MPE values are the definitive safety thresholds, particularly in LiDAR applications where exposure duration and area are highly relevant. LiDAR operators must adhere to MPE limits to prevent eye damage, especially in scenarios involving prolonged exposure to laser emissions.
