Im working on a project with a 150mw green laser module with an adjustable focus ring .can i make the beam out of focus and also put a small lens in front of the beam to make it show a 5" round beam at 10ft from the laser? Will this make it safe if someone happens to look into it? Thank you for you advice. Guy
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150mw 532nm 5 volt green laser module
- Thread starter strat1953
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Yes, 150mW in a >5 inch beam should be safe.
Maximum permissible exposure (MPE) is 1mW/cm². If we assume a top-hat beam profile (to make calculations simpler), at 10 feet, your laser will have power density of:
power/area
150mW/(pi*r²)
150mW/(pi*(6.35cm)²)
1.18mW/cm²
Of course, MPE doesn't mean complete safety at 0.99mW/cm² and instant death at 1.01mW/cm². It is relatively common for lasershows to audience scan at 10x MPE or even 100x MPE in some parts of europe.
Maximum permissible exposure (MPE) is 1mW/cm². If we assume a top-hat beam profile (to make calculations simpler), at 10 feet, your laser will have power density of:
power/area
150mW/(pi*r²)
150mW/(pi*(6.35cm)²)
1.18mW/cm²
Of course, MPE doesn't mean complete safety at 0.99mW/cm² and instant death at 1.01mW/cm². It is relatively common for lasershows to audience scan at 10x MPE or even 100x MPE in some parts of europe.