Knowledge Bank

Polarization modulation in the far infared region is not easily achieved due to the strong far infrared absorbance of the material based optical elements. Polarization division interferometry (PDI) overcomes this problem in a unique way. Using a far-infrared PDI developed in our laboratory, the performance of PDI is evaluated by measuring the circular dichroism of $\alpha$-pinene, camphor and 3-methyleyelohexanone and linear dichroism of oriented polyvinylfluoride. These measurements establish the utility of PDI to measure transmission, circular dichroism and linear dichroism spectra in the far-infrared region ($-600.10cm-1$) without need for any additional components. The dichroic multiplex advantage (ability to measure dichroism in the entire far-infrared region from a single measurement) and throughput advantage are demonstrated.