Raman spectra of two optical glasses (a borosilicate crown and a dense flint glass) have been obtained making use of unpolarized exciting light and also with parallel and perpendicular plane polarized exciting light. The chief characteristics of these spectra are that they consist essentially of continua with broad maxima in the continua. The main features of the Raman spectra of these glasses are strongly polarized. In the photograph made with parallel polarized exciting light, a very strong depolarized line only 30-cm−1 frequency shift from the exciting line makes its appearance in the spectrum of the flint glass.
An attempt has been made to find modified Brillouin components in the Rayleigh line. Photographs of λ-4047 and λ-4078 made in the third order of a 21-foot concave grating show no modified Brillouin components which are 1/100 as strong as the unmodified line.
The polarization of the Rayleigh scattering of these glasses has been investigated. The intensities of the polarized components were measured by means of photoelectric methods. Measurements made with polarized exciting light show definitely that ρh is somewhat less than unity, which definitely verifies the existence of a Krishnan effect in these glasses.
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