Polarisation of Raman scattering by hydrogen gas

Abstract

The theoretical work of Hill and Kemble, Manneback, and others, indicates that in the spectrum of the light scattered transversely by diatomic molecules, the rotational lines should be very imperfectly polarised. The Raman spectrum of hydrogen offers a particularly favourable case for an experimental test of this point, as the individual rotational lines are well separated from the exciting line. Working at a pressure of 50 atm. I have observed that the Raman lines representing the rotational transitions 0→2 and 1→3 in hydrogen gas are only weakly polarised, that is, to the extent of about 25 per cent; and that, on the other hand, the polarisation of the vibration lines appears to be sensibly complete.