Ruby lases at a wavelength of 694 nm. A certain ruby crystal has `4.00xx10^(19)Cr` ions (which are the atoms that lase). The lasing transition is between the first excited state and the ground state, and the output is a light pulse lasting `1.50mus`. As the pulse begins, 60.0% of the Cr ions are in the first excited state and the rest are in the ground state. What is the average power emitted during the pulse?

Explanation

`1.5xx10^(6)J//s=1.5xx10^(6)W`