I am building a laser room and I'm basically trying to calculate the maximum time of laser radiation to they eye before causing any harm. I found that to be 7 seconds but I would very much appreciate if someone familiar with this topic can confirm that my calculations are accurate.
The lasers I use are green ones @352nm 50mW. Based on the MPE and coefficient tables, the formula for Hmpe = C1 J/m^2 = 5.6 x 10^3 x (t^0.25) J/m^2 = 5.6 x 10^3 x (7^0.25) J/m^2 = 9.1 x 10^ 3 J/m^2
In terms of irradiance obtained after dividing by t = 7s:
Empe = 1.3 W/m^2
Now, from here "considering the limiting aperture of they eye in the visible region, 7mm, then the area over which the visible radiation will be viewed is π/4×0.7^2 = 0.385 cm2 = 3.85 * 10^-5 m^2 "
, the maximum power to avoid harm due to eye exposure is:
3.85 * 10^-5 * 1.2 * 10^3 W = 0.05W =50mW which is my lasers's output power.
You think this calculation is accurate?
Thank you in advance, Dimitris