Question

how many photons are produced in a laser pulse od 0.301 J at 655 nm?

Answer 1

Answer

9.92 × 10¹⁷ photons

Explanation

Energy of photon , E = h c /$\lambda$

where,

h = planck constant , 6.626 ×10^-34 J.s

c = speed of light , 2.998×10⁸m/s

  $\lambda$ = wavelength of photon , 655nm = 655 ×10^-9m

E = 6.626 ×10^-34 J.s ( 2.998 × 10⁸m/s/655×10^-9m)

E = 3.033 × 10^-19J

Number of photons produced = 0.301J/3.033×10^-19J /photon = 9.92 × 10¹⁷ photons