Laser goggles are protective equipment that reduces or prevents laser damage to the human eye by absorbing or reflecting specific wavelengths of laser radiation.
The working principle of laser goggles is similar to a neutral density filter, which disperses laser energy. However, unlike ND filters, laser goggles only block a specific range of wavelengths, allowing users to maintain a certain degree of visibility. Although laser goggles may have sufficient density to protect users, they must also be able to provide this level of protection without immediately burning out.
The EN207 directive requires that laser goggles must be able to protect users for at least 10 seconds (Class D) or 100 pulses (Class I and R) when exposed to laser radiation, without any malfunctions.
D level is applicable to continuous wave lasers or lasers with pulse duration exceeding 0.2 seconds, with power measured in W/m ². The maximum average power of the laser should be used. The I standard is applicable to pulse lasers with pulse durations ranging from 0.25 seconds to 10 ^ -6 seconds, while the R standard is applicable to pulse lasers with pulse durations ranging from 10 ^ -6 seconds to 10 ^ -9 seconds, both measured in J/m ². In addition, there is an M-class for lasers with pulse lengths less than 10 ^ -9 seconds, but currently none of our existing goggles series can protect against such high-frequency lasers.
L level is an indicator that measures the ability of goggles to respond to laser radiation, consisting of 10 levels corresponding to optical density. It considers the maximum power or energy density that the goggles can absorb in the shortest possible time without performance degradation, while also taking into account the spectral transmittance at the laser wavelength. If these two indicators represent different L levels, use the lower L number.
The L level is further subdivided into three bands, which take into account the ability of the eye to naturally block shorter wavelengths. The first band covers the wavelength range between 180 and 315 nanometers, the second band covers 316 nanometers to 1400 nanometers, and the third band covers 1401 nanometers to 1000 micrometers.