Question

How many photons are produced in a laser pulse of 0.649 J at 535 nm?

Answer 1

use this relaTION
\[E=H \nu \]
where E is the energy of a single photon, and ν is the frequency of a single photon
again if a photon traveling at the speed of light c and a frequency ν will have a wavelength λ given by
\[\lambda=c/\nu \]
\[E=hc/λ\]
\[E=(6.626×10^{-34})(2.998×10^{8})/(535×10^{-9})=3.71×10^{-19} J\]
To find out how many photons are in a laser pulse of 0.649 Joules, we simply divide the pulse energy by the photon energy
so number pf photons
\[N=\frac{ 0.649 }{ 3.71*10^{-19} }=1.7*10^{18}\]

Answer 2

Well explained.