•One photon from a 488 nm argon
laser has an energy of
–E= 6.63x10-34 joule-seconds x 3x108
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–
•To get 1 joule out of a 488 nm
laser you need 2.45 x 1018 photons
•1 watt (W) = 1 joule/second a 10
mW laser at 488 nm is putting out 2.45x1016 photons/sec
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