Question
A $640-\mathrm{nm}$ laser emits a one-second pulse in a beam with a diameter of $1.5 \mathrm{~mm}$. The rms electric field of the pulse is $120 \mathrm{~V} / \mathrm{m}$. How many photons are emitted per second?
Step 1
First, we need to find the energy of a single photon. We can use the formula: Energy (E) = (Planck's constant) × (speed of light) / (wavelength) where Planck's constant (h) = 6.63 × 10^(-34) Js, the speed of light (c) = 3 × 10^8 m/s, and the wavelength (λ) Show more…
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