Nonlinear optics solution to the mystery of the diffuse optical interstellar bands (DIBs)

For more than 60 years, scientists have speculated about the origin of the so-called diffuse optical interstellar bands (DIBs), a complex pattern of more than 200 absorption bands of varying widths appearing in the visible part of the spectrum in the frequency-dispersed light from reddened bright stars. With use of a model based on nonlinear absorption by H2, the authors believe they are en route to a solution of this mystery.