Author Question: A ruby laser delivers a 2.28-J pulse in approximately 50 nanoseconds. The wavelength of the light is ... (Read 82 times)

olgavictoria · **on:** Jul 28, 2018

A ruby laser delivers a 2.28-J pulse in approximately 50 nanoseconds. The wavelength of the light is 694.4 nm. At least how many atoms within the ruby rod had to be excited to allow this high-energy laser pulse? (h = 6.63 10-34 Js, c = 3.00 108 m/s, 1 eV = 1.6 10-19 J, and 1 nm = 10-9 m)
a. 3 1019
c. 8 1018
b. 4 1018
d. 6 1020

Question 2

The wavelength of a coherent laser is 628 nm. What energy difference exists between the upper excited state involved and the lower unexcited ground state? (h = 6.63 10-34 Js, c = 3.00 108 m/s, 1 eV = 1.60 10-19 J, and 1 nm = 10-9 m)
a. 1.86 eV
c. 1.75 eV
b. 1.81 eV
d. 1.98 eV