  Dielectric tensor tomography (DTT) enables the reconstruction of
three-dimensional (3D) dielectric tensors, which provides a physical measure of
3D optical anisotropy. Herein, we present a cost-effective and robust method
for DTT measurement using a multiplexing approach. By exploiting two
orthogonally polarized reference beams with different angles in an off-axis
interferometer, two polarization-sensitive interferograms were overlapped and
recorded using a single camera. Then, the two multiplexed interferograms were
separated in the Fourier domain, enabling the reconstruction of
polarization-sensitive fields. Finally, by measuring the polarization-sensitive
fields for various illumination angles, 3D dielectric tensor tomograms were
reconstructed. The proposed method was experimentally demonstrated by
reconstructing the 3D dielectric tensors of various liquid crystal particles
with radial and bipolar orientational configurations.
