Knowledge Bank

Interaction between incident electromagnetic radiation and the regular groove structure of a diffraction grating gives rise to polarization phenomena whenever the groove spacing is less than about 5 times the wave-length. Theory predicts the general behavior but fails to account for some of the details observed experimentally. For many problems in I.R. spectroscopy and T.R. lasers, it is important to be aware of what actually takes place. Special equipment for obtaining data on diffracted energy in both planes of polarization will be described and results typical of commonly used gratings will be compared with theory.