Anomalies in the polarized raman spectrum of crystal quartz

Summary By means of coherent Raman scattering we have measured in quartz the dispersion of the elements of the Raman tensor in the range (900÷1070) cm⁻¹. The results determine with good accuracy the relative contribution of the various modes to the second-order nonlinear susceptibility. For some elements of the Raman tensor the present results greatly improve the precision of data already known; for others the dispersion and the relative strengths have been measured for the first time. In particular, a strong, frequency-dependent, asymmetry of the Raman tensor has been evidentiated; this asymmetry is interpreted in terms of optical Raman activity.