The laser has the characteristics of strong directivity, good monochromaticity, good coherence, etc., making it widely used in military, industrial and medical fields. But it is these characteristics of the laser that pose a great threat to the human body. The eye is the most sensitive organ of the human body to the laser. Due to the focusing effect of the eye on the light, the energy density on the retina can be increased by 105 times. Therefore, low-dose irradiation can cause serious damage to the retina and cause vision loss until blindness. How to carry out effective laser protection has become a matter of great concern to people, and countries have formulated laser protection standards accordingly. As early as 1962, the United States proposed some laser safety exposure limits.
Now the mandatory standards for laser safety in my country are:
CJB-2408-95 Laser protective glasses protective performance test method
GJB-1762-93 Laser protection glasses physiological sanitation protection requirements
JB / T 5524-91 Laboratory laser safety rules
There are many types of laser protective glasses, the materials used are different, the principles are different, and the applications are also different. Therefore, to provide effective protection to the laser, the laser protective glasses must be reasonably selected according to the specific use requirements. When selecting protective glasses, first determine the maximum irradiance or maximum irradiance of the laser output according to the parameters of the maximum output power (or energy), beam diameter, pulse time and other parameters of the laser used. Then, determine the minimum optical density required for the glasses according to the maximum allowable irradiation amount (eye exposure limit) of the corresponding wavelength and irradiation time, and select appropriate protective glasses accordingly.
The specific conditions for selection are:
1. Maximum irradiance Hmax (J / m2) or maximum irradiance Emax (W / m2);
2. Specific protection wavelength;
3. The required minimum optical density value Dmin at the corresponding protection wavelength;
4. Non-uniformity, asymmetry of protective lens, angle effect of incident light, etc .;
5. Resistance to laser radiation;
6. Visible light transmittance;
7. Structure and appearance.