Fig. 3: Optical anisotropy of 1 driven by the structural transformation.

a A scheme of the ST of 1 in polar coordinates revealed by SCXRD (Supplementary Tables S1–S3). b Spatial dispersion of refractive index n for (100) and (110) planes of 1 (Supplementary Figs. S23, S24) before and during the ST, initiated by laser-induced heating (1050 nm, 4.5 mW of pumping laser power; green curve corresponds to the initial state, while the red one is for the excited state). c, d The dynamics of the ST expressed as the evolution of the intensity of 450 nm probing laser light with a varied polarization (0°–180°) passing through the single crystal of 1 during the ST, stimulated by a single 1064 nm (100 ns) laser pulse (red curve corresponds to the relaxation time in (c), while the green one is for the excitation time; green and red curves in (d) correspond to 0° and 90° polarization of the probing laser light). e, f Scheme and the experimentally measured rotation of the polarization of the probing laser light of a varied wavelength (580–720 nm, fluence of 0.28 mJ cm⁻²) over time (inset) passing through the single crystal of 1 (of 100 µm thick and an arbitrary orientation) during the ST, stimulated by the laser irradiation (1050 nm, fluence of 3 mJ cm⁻²).