Generation of elliptically and circularly polarized infrared waves by incidence of randomly polarized light through α-quartz

In the absorptive frequency region of α  -quartz, there exist several sharp transmission windows in the infrared range. By incidence of randomly polarized light, the transmitted waves from the transmission windows are polarized in two eigenvibration directions, corresponding to the ordinary and extraordinary waves, respectively. There is a phase shift of ∼π/2∼π/2 between them after passing through the crystal, producing the elliptically polarized waves and even circularly polarized waves at some frequencies. The polarization state of the eigenmodes is resulted from the interaction of the incident waves with α-quartz.