Quote:
If you want to have a clean conscious and be responsible, including pictures and educational material on how to calculate power density at a distance pertaining to the 445nm diode.
end quote,
We have done that several times on PL. I'll ask Spec to make a sticky for it.
Getting the copywrited ANSI lookup table requires you to purchase the Z136 standard. However It is available for free, I've posted the file here, and on LPF many times before, A excellent copy of the chart is in Army Medical Publicaton TB 524
Which is available here: http://chppm-www.apgea.army.mil/laser/Main.html
Or by goggling "Army Laser Safety"
The calculation examples are in Appendix B on Page 111 and the tables for wavelength specific numbers start on Page 207
The CDRH's own Audience Scanning Calcs are here, from the last flame war we had about calculation methods on PL:
http://www.photonlexicon.com/forums/...ing%20mixedgas
A reduced function on line calculator is here:
http://www.laser-professionals.com/p....php?pageid=54
It has issues with short distances and non circular beams however.
PL user DOC has a spreadsheet here:
http://www.photonlexicon.com/forums/...5&d=1261568920
Again, for mainly circular beams.
Caveats, Measuring divergence is problematic in a multimode broad stripe laser diode such as these. Most simple methods assume TEM00 mode, and these are ANYTHING BUT TEM. Good methods involve a power meter or photodiode, a translation stage and a knife edge. Otherwise it is difficult to make accurate assumptions based on shining the spot on the wall and using a ruler to guess the 1/e^2 points.
Understanding the math is problematic for most people. Rob, why don't you write a JAVA calculator and stick it on line some place.
445 is in the actinic range, as is 405, so the hazard number is a bit different then the straight visual table.
Steve