Method for birefringence measurements as a function of wavelength in the visible range, applied to the reinvestigation of crystal quartz

Abstract

An experimental method for the accurate measurement of the optical birefringence of thick anisotropic crystal plates using optical modulation of the incident light beam is described in detail. The significant advantages in the present experimental method over previous ones are the extension of the measurements to more than one wavelength and its efficiency in measuring the absolute value of the birefringence of any crystal, even if its optical properties are unknown. The method is applied, as an example, to the measurement of the birefringence of crystal quartz as a function of wavelength in the visible range. The experimental results we have obtained for quartz at room temperature are reported and discussed. Comparison of the values of the birefringence of quartz with those published in the literature proves that our method allows the determination of the optical birefringence with an accuracy of .