A criterion for using spectral interferometry in far infrared dispersion measurements
Résumé
High precision index measurements (Δn/n ≤ 10-5) have been recently achieved on an AgGaS2 crystal using a spectral interferometry technique with a polarized white-light continuum. Up to now, these measurements are limited to the visible and near-infrared range, the most dispersive domain. We investigate the possibility to extend the technique to far infrared index measurements. We demonstrate a criterion depending only on group velocity dispersion and crystal thickness for planning future experiments.