This causes an absorption spectra, as shown below. Because the energy levels are the same, the lines in the emission spectra of an element are in the same position as the lines in the absorption ...

This causes line emission spectra to be produced, as shown below. This is not a continuous spectrum as only light of specific frequencies and specific colours are produced. Different types of ...

Optical frequency combs—which emit thousands of regularly spaced spectral lines—have transformed fields like metrology, ...