I have a compliance audit that has been foisted on me from on high - as part of what an external consultancy has highlighted, I now have to prove that the indicator LEDs on a board I designed a long time ago are Class 1 laser compliant. Please do not point out how ridiculous this is.
I have the following specs for the LEDs in question:
- peak wavelength (595 nm)
- dominant wavelength (590 nm)
- spectral bandwidth (15 nm)
- luminous intensity (120 mcd)
- viewing angle (defined as the angle across which luminous intensity is 50% or more of maximum - 140º)
The Wikipedia article on laser safety has this chart of maximum allowed CW power at various wavelengths and for various classes. It states that it is only valid for weakly divergent or collimated laser beams, but since Class 1 devices must be safe to view using any optical equipment, I can make the assumption that they are valid for the case where there exists a lens that can concentrate all of the available optical power from the LED onto the retina.
My big issue is that I can't seem to work out how to go from luminous intensity to optical power. I can convert from luminous intensity to luminous flux - however not to radiant flux (which I believe is equivalent to total optical power).
Can anyone shove me in the right direction?