Famous 'Aspect Experiment' -- Which Type of Polarizers Were Used?

[d_bar_x]

TL;DR Summary

Which type of polarizers were used?

Does anyone know exactly which kind of polarizers were used in the famous Aspect experiment from 1982? I've read they were crystal polarizers. Does that mean Calcite, or Nicol, or something else?

[Reference link added by the Mentors:]

https://en.wikipedia.org/wiki/Aspect's_experiment

 

[pines-demon]

With the use of two-channel polarizers, we have performed an experimentfollowing much more closely the ideal scheme of Figure 1. Our polarizers were polarizingcubes with dielectric layers transmitting one polarization and reflecting the orthogonalone††

††A similar experiment, using calcite two channel polarizers, had been considered at the University ofCatania

from https://arxiv.org/abs/quant-ph/0402001 it is true that not much more is said. I would guess calcite.