Is there some sort of chart showing what OD rating you need in goggles to protect from the mw of a laser? So if you have N amount of mw, what Od do you need?
Since you don't want to research it (as it's all over the safety section), the actual calculation is:
OD = log[sub]10[/sub](E[sub]i[/sub]/E[sub]t[/sub])
Where E[sub]i[/sub] is the incident beam energy (generally in W/cm[sup]2[/sup]) and
where E[sub]t[/sub] is the transmitted beam energy (generally in W/cm[sup]2[/sup])
Because you are dividing E[sub]i[/sub] by E[sub]t[/sub] you have a ratio and thus can use any power rating as long as the incident and the transmitted power are the same units.
Here is an example:
Laser Maximum Output: 200mW
Maximum Transmitted Power: 5mW (keep the exposure at or below Class IIIa levels)
OD = log[sub]10[/sub](200mW/5mW)
OD = log[sub]10[/sub](40)
OD = 1.602059991
Thus if I have a 200mW laser and I want to allow no more than 5mW to pass through the lens I will need protective eyewear rated at least OD 1.60205991 at the laser wavelength.
Seriously though, why don't people research more before asking questions?
I take pride in being able to find my own answers, without having to pose public questions. Posing a public question is kinda like admitting defeat - I lost my personal battle of finding the answers for myself.