Problem 4: Ruby lasers have chromium atoms doped in an aluminum oxide crystal. The energy level diagram for chromium in a ruby is shown in the figure. Part (a) What energy photons can pump chromium atoms in a ruby laser from the ground state to its second excited state in eV? Part (b) What is the wavelength of this photon in nm? Part (c) What part of the visible light spectrum is it?

Problem 4: Ruby lasers have chromium atoms doped in an aluminum oxide crystal. The energy level diagram for chromium in a ruby is shown in the figure. Part (a) What energy photons can pump chromium atoms in a ruby laser from the ground state to its second excited state in eV? Part (b) What is the wavelength of this photon in nm? Part (c) What part of the visible light spectrum is it?