Fig. 1: Principle and experimental setup for spatially resolved optical activity measurements.

a, Experimental setup of the polarization-sensitive off-axis holography system. b, Linearly polarized light can be decomposed into LCP and RCP at equal amplitudes. After passing through a chiral sample, the initial linear polarization is transformed into elliptical polarization with a tilted plane of polarization. c, The two reference beams, one in the LCP state and one in the RCP state, interfere with the sample beam at different angles, leading to multiplexed hologram encoding. d, Hologram of an array of chiral nanostructures. Scale bar, 50 mm. e, Fourier transform of the hologram. The contributions corresponding to the LCP and RCP components are spatially isolated (as indicated by the dashed circles). PBS, polarizing beamsplitter; WP, Wollaston prism; QWP, quarter-wave plate; BS, beamsplitter; FFT, fast Fourier transform; HWP, half-wave plate; LP, linear polarizer.