Fig. 3: Polarizing microscope-based birefringence characterization of Hg18Ga8Se8Cl32 (140 K).
From: [Hg3Se2]2- cluster drives giant optical anisotropy and broad infrared transparency
a Schematic illustration of the optical setup for birefringence measurement using a polarizing microscope. b Polarizing microscopy images of the HGSC crystal under cross-polarized conditions at various rotation angles (0° to 180°, step = 15°). c Microscopic image of the HGSC sample used for measurement, with a thickness of 14 μm. d, e Images captured during positive and negative rotation of the compensator at the characteristic wavelength of 546.1 nm for accurate determination of the optical path difference.
