A certain laser transition emits $6.37\times10^{15}$ quants per second per square meter. Calculate the power out put in joule per square metre per second. Given $\lambda$ = 632.8 nm.

Question

$(a)2\times10^{-3}J/m^2/sec\qquad(b)1\times10^{-2}J/m^2/sec\qquad(c)2\times10J/m^2/sec\qquad(d)1\times10J/m^2/sec$